Line data Source code
1 : /* Scalar evolution detector.
2 : Copyright (C) 2003-2026 Free Software Foundation, Inc.
3 : Contributed by Sebastian Pop <s.pop@laposte.net>
4 :
5 : This file is part of GCC.
6 :
7 : GCC is free software; you can redistribute it and/or modify it under
8 : the terms of the GNU General Public License as published by the Free
9 : Software Foundation; either version 3, or (at your option) any later
10 : version.
11 :
12 : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 : WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 : for more details.
16 :
17 : You should have received a copy of the GNU General Public License
18 : along with GCC; see the file COPYING3. If not see
19 : <http://www.gnu.org/licenses/>. */
20 :
21 : /*
22 : Description:
23 :
24 : This pass analyzes the evolution of scalar variables in loop
25 : structures. The algorithm is based on the SSA representation,
26 : and on the loop hierarchy tree. This algorithm is not based on
27 : the notion of versions of a variable, as it was the case for the
28 : previous implementations of the scalar evolution algorithm, but
29 : it assumes that each defined name is unique.
30 :
31 : The notation used in this file is called "chains of recurrences",
32 : and has been proposed by Eugene Zima, Robert Van Engelen, and
33 : others for describing induction variables in programs. For example
34 : "b -> {0, +, 2}_1" means that the scalar variable "b" is equal to 0
35 : when entering in the loop_1 and has a step 2 in this loop, in other
36 : words "for (b = 0; b < N; b+=2);". Note that the coefficients of
37 : this chain of recurrence (or chrec [shrek]) can contain the name of
38 : other variables, in which case they are called parametric chrecs.
39 : For example, "b -> {a, +, 2}_1" means that the initial value of "b"
40 : is the value of "a". In most of the cases these parametric chrecs
41 : are fully instantiated before their use because symbolic names can
42 : hide some difficult cases such as self-references described later
43 : (see the Fibonacci example).
44 :
45 : A short sketch of the algorithm is:
46 :
47 : Given a scalar variable to be analyzed, follow the SSA edge to
48 : its definition:
49 :
50 : - When the definition is a GIMPLE_ASSIGN: if the right hand side
51 : (RHS) of the definition cannot be statically analyzed, the answer
52 : of the analyzer is: "don't know".
53 : Otherwise, for all the variables that are not yet analyzed in the
54 : RHS, try to determine their evolution, and finally try to
55 : evaluate the operation of the RHS that gives the evolution
56 : function of the analyzed variable.
57 :
58 : - When the definition is a condition-phi-node: determine the
59 : evolution function for all the branches of the phi node, and
60 : finally merge these evolutions (see chrec_merge).
61 :
62 : - When the definition is a loop-phi-node: determine its initial
63 : condition, that is the SSA edge defined in an outer loop, and
64 : keep it symbolic. Then determine the SSA edges that are defined
65 : in the body of the loop. Follow the inner edges until ending on
66 : another loop-phi-node of the same analyzed loop. If the reached
67 : loop-phi-node is not the starting loop-phi-node, then we keep
68 : this definition under a symbolic form. If the reached
69 : loop-phi-node is the same as the starting one, then we compute a
70 : symbolic stride on the return path. The result is then the
71 : symbolic chrec {initial_condition, +, symbolic_stride}_loop.
72 :
73 : Examples:
74 :
75 : Example 1: Illustration of the basic algorithm.
76 :
77 : | a = 3
78 : | loop_1
79 : | b = phi (a, c)
80 : | c = b + 1
81 : | if (c > 10) exit_loop
82 : | endloop
83 :
84 : Suppose that we want to know the number of iterations of the
85 : loop_1. The exit_loop is controlled by a COND_EXPR (c > 10). We
86 : ask the scalar evolution analyzer two questions: what's the
87 : scalar evolution (scev) of "c", and what's the scev of "10". For
88 : "10" the answer is "10" since it is a scalar constant. For the
89 : scalar variable "c", it follows the SSA edge to its definition,
90 : "c = b + 1", and then asks again what's the scev of "b".
91 : Following the SSA edge, we end on a loop-phi-node "b = phi (a,
92 : c)", where the initial condition is "a", and the inner loop edge
93 : is "c". The initial condition is kept under a symbolic form (it
94 : may be the case that the copy constant propagation has done its
95 : work and we end with the constant "3" as one of the edges of the
96 : loop-phi-node). The update edge is followed to the end of the
97 : loop, and until reaching again the starting loop-phi-node: b -> c
98 : -> b. At this point we have drawn a path from "b" to "b" from
99 : which we compute the stride in the loop: in this example it is
100 : "+1". The resulting scev for "b" is "b -> {a, +, 1}_1". Now
101 : that the scev for "b" is known, it is possible to compute the
102 : scev for "c", that is "c -> {a + 1, +, 1}_1". In order to
103 : determine the number of iterations in the loop_1, we have to
104 : instantiate_parameters (loop_1, {a + 1, +, 1}_1), that gives after some
105 : more analysis the scev {4, +, 1}_1, or in other words, this is
106 : the function "f (x) = x + 4", where x is the iteration count of
107 : the loop_1. Now we have to solve the inequality "x + 4 > 10",
108 : and take the smallest iteration number for which the loop is
109 : exited: x = 7. This loop runs from x = 0 to x = 7, and in total
110 : there are 8 iterations. In terms of loop normalization, we have
111 : created a variable that is implicitly defined, "x" or just "_1",
112 : and all the other analyzed scalars of the loop are defined in
113 : function of this variable:
114 :
115 : a -> 3
116 : b -> {3, +, 1}_1
117 : c -> {4, +, 1}_1
118 :
119 : or in terms of a C program:
120 :
121 : | a = 3
122 : | for (x = 0; x <= 7; x++)
123 : | {
124 : | b = x + 3
125 : | c = x + 4
126 : | }
127 :
128 : Example 2a: Illustration of the algorithm on nested loops.
129 :
130 : | loop_1
131 : | a = phi (1, b)
132 : | c = a + 2
133 : | loop_2 10 times
134 : | b = phi (c, d)
135 : | d = b + 3
136 : | endloop
137 : | endloop
138 :
139 : For analyzing the scalar evolution of "a", the algorithm follows
140 : the SSA edge into the loop's body: "a -> b". "b" is an inner
141 : loop-phi-node, and its analysis as in Example 1, gives:
142 :
143 : b -> {c, +, 3}_2
144 : d -> {c + 3, +, 3}_2
145 :
146 : Following the SSA edge for the initial condition, we end on "c = a
147 : + 2", and then on the starting loop-phi-node "a". From this point,
148 : the loop stride is computed: back on "c = a + 2" we get a "+2" in
149 : the loop_1, then on the loop-phi-node "b" we compute the overall
150 : effect of the inner loop that is "b = c + 30", and we get a "+30"
151 : in the loop_1. That means that the overall stride in loop_1 is
152 : equal to "+32", and the result is:
153 :
154 : a -> {1, +, 32}_1
155 : c -> {3, +, 32}_1
156 :
157 : Example 2b: Multivariate chains of recurrences.
158 :
159 : | loop_1
160 : | k = phi (0, k + 1)
161 : | loop_2 4 times
162 : | j = phi (0, j + 1)
163 : | loop_3 4 times
164 : | i = phi (0, i + 1)
165 : | A[j + k] = ...
166 : | endloop
167 : | endloop
168 : | endloop
169 :
170 : Analyzing the access function of array A with
171 : instantiate_parameters (loop_1, "j + k"), we obtain the
172 : instantiation and the analysis of the scalar variables "j" and "k"
173 : in loop_1. This leads to the scalar evolution {4, +, 1}_1: the end
174 : value of loop_2 for "j" is 4, and the evolution of "k" in loop_1 is
175 : {0, +, 1}_1. To obtain the evolution function in loop_3 and
176 : instantiate the scalar variables up to loop_1, one has to use:
177 : instantiate_scev (block_before_loop (loop_1), loop_3, "j + k").
178 : The result of this call is {{0, +, 1}_1, +, 1}_2.
179 :
180 : Example 3: Higher degree polynomials.
181 :
182 : | loop_1
183 : | a = phi (2, b)
184 : | c = phi (5, d)
185 : | b = a + 1
186 : | d = c + a
187 : | endloop
188 :
189 : a -> {2, +, 1}_1
190 : b -> {3, +, 1}_1
191 : c -> {5, +, a}_1
192 : d -> {5 + a, +, a}_1
193 :
194 : instantiate_parameters (loop_1, {5, +, a}_1) -> {5, +, 2, +, 1}_1
195 : instantiate_parameters (loop_1, {5 + a, +, a}_1) -> {7, +, 3, +, 1}_1
196 :
197 : Example 4: Lucas, Fibonacci, or mixers in general.
198 :
199 : | loop_1
200 : | a = phi (1, b)
201 : | c = phi (3, d)
202 : | b = c
203 : | d = c + a
204 : | endloop
205 :
206 : a -> (1, c)_1
207 : c -> {3, +, a}_1
208 :
209 : The syntax "(1, c)_1" stands for a PEELED_CHREC that has the
210 : following semantics: during the first iteration of the loop_1, the
211 : variable contains the value 1, and then it contains the value "c".
212 : Note that this syntax is close to the syntax of the loop-phi-node:
213 : "a -> (1, c)_1" vs. "a = phi (1, c)".
214 :
215 : The symbolic chrec representation contains all the semantics of the
216 : original code. What is more difficult is to use this information.
217 :
218 : Example 5: Flip-flops, or exchangers.
219 :
220 : | loop_1
221 : | a = phi (1, b)
222 : | c = phi (3, d)
223 : | b = c
224 : | d = a
225 : | endloop
226 :
227 : a -> (1, c)_1
228 : c -> (3, a)_1
229 :
230 : Based on these symbolic chrecs, it is possible to refine this
231 : information into the more precise PERIODIC_CHRECs:
232 :
233 : a -> |1, 3|_1
234 : c -> |3, 1|_1
235 :
236 : This transformation is not yet implemented.
237 :
238 : Further readings:
239 :
240 : You can find a more detailed description of the algorithm in:
241 : http://icps.u-strasbg.fr/~pop/DEA_03_Pop.pdf
242 : http://icps.u-strasbg.fr/~pop/DEA_03_Pop.ps.gz. But note that
243 : this is a preliminary report and some of the details of the
244 : algorithm have changed. I'm working on a research report that
245 : updates the description of the algorithms to reflect the design
246 : choices used in this implementation.
247 :
248 : A set of slides show a high level overview of the algorithm and run
249 : an example through the scalar evolution analyzer:
250 : http://cri.ensmp.fr/~pop/gcc/mar04/slides.pdf
251 :
252 : The slides that I have presented at the GCC Summit'04 are available
253 : at: http://cri.ensmp.fr/~pop/gcc/20040604/gccsummit-lno-spop.pdf
254 : */
255 :
256 : #include "config.h"
257 : #include "system.h"
258 : #include "coretypes.h"
259 : #include "backend.h"
260 : #include "target.h"
261 : #include "rtl.h"
262 : #include "optabs-query.h"
263 : #include "tree.h"
264 : #include "gimple.h"
265 : #include "ssa.h"
266 : #include "gimple-pretty-print.h"
267 : #include "fold-const.h"
268 : #include "gimplify.h"
269 : #include "gimple-iterator.h"
270 : #include "gimplify-me.h"
271 : #include "tree-cfg.h"
272 : #include "tree-ssa-loop-ivopts.h"
273 : #include "tree-ssa-loop-manip.h"
274 : #include "tree-ssa-loop-niter.h"
275 : #include "tree-ssa-loop.h"
276 : #include "tree-ssa.h"
277 : #include "cfgloop.h"
278 : #include "tree-chrec.h"
279 : #include "tree-affine.h"
280 : #include "tree-scalar-evolution.h"
281 : #include "dumpfile.h"
282 : #include "tree-ssa-propagate.h"
283 : #include "gimple-fold.h"
284 : #include "tree-into-ssa.h"
285 : #include "builtins.h"
286 : #include "case-cfn-macros.h"
287 : #include "tree-eh.h"
288 :
289 : static tree analyze_scalar_evolution_1 (class loop *, tree);
290 : static tree analyze_scalar_evolution_for_address_of (class loop *loop,
291 : tree var);
292 :
293 : /* The cached information about an SSA name with version NAME_VERSION,
294 : claiming that below basic block with index INSTANTIATED_BELOW, the
295 : value of the SSA name can be expressed as CHREC. */
296 :
297 : struct GTY((for_user)) scev_info_str {
298 : unsigned int name_version;
299 : int instantiated_below;
300 : tree chrec;
301 : };
302 :
303 : /* Counters for the scev database. */
304 : static unsigned nb_set_scev = 0;
305 : static unsigned nb_get_scev = 0;
306 :
307 : struct scev_info_hasher : ggc_ptr_hash<scev_info_str>
308 : {
309 : static hashval_t hash (scev_info_str *i);
310 : static bool equal (const scev_info_str *a, const scev_info_str *b);
311 : };
312 :
313 : static GTY (()) hash_table<scev_info_hasher> *scalar_evolution_info;
314 :
315 :
316 : /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */
317 :
318 : static inline struct scev_info_str *
319 52317415 : new_scev_info_str (basic_block instantiated_below, tree var)
320 : {
321 52317415 : struct scev_info_str *res;
322 :
323 52317415 : res = ggc_alloc<scev_info_str> ();
324 52317415 : res->name_version = SSA_NAME_VERSION (var);
325 52317415 : res->chrec = chrec_not_analyzed_yet;
326 52317415 : res->instantiated_below = instantiated_below->index;
327 :
328 52317415 : return res;
329 : }
330 :
331 : /* Computes a hash function for database element ELT. */
332 :
333 : hashval_t
334 1067912200 : scev_info_hasher::hash (scev_info_str *elt)
335 : {
336 1067912200 : return elt->name_version ^ elt->instantiated_below;
337 : }
338 :
339 : /* Compares database elements E1 and E2. */
340 :
341 : bool
342 1058463387 : scev_info_hasher::equal (const scev_info_str *elt1, const scev_info_str *elt2)
343 : {
344 1058463387 : return (elt1->name_version == elt2->name_version
345 1058463387 : && elt1->instantiated_below == elt2->instantiated_below);
346 : }
347 :
348 : /* Get the scalar evolution of VAR for INSTANTIATED_BELOW basic block.
349 : A first query on VAR returns chrec_not_analyzed_yet. */
350 :
351 : static tree *
352 205755772 : find_var_scev_info (basic_block instantiated_below, tree var)
353 : {
354 205755772 : struct scev_info_str *res;
355 205755772 : struct scev_info_str tmp;
356 :
357 205755772 : tmp.name_version = SSA_NAME_VERSION (var);
358 205755772 : tmp.instantiated_below = instantiated_below->index;
359 205755772 : scev_info_str **slot = scalar_evolution_info->find_slot (&tmp, INSERT);
360 :
361 205755772 : if (!*slot)
362 52317415 : *slot = new_scev_info_str (instantiated_below, var);
363 205755772 : res = *slot;
364 :
365 205755772 : return &res->chrec;
366 : }
367 :
368 :
369 : /* Hashtable helpers for a temporary hash-table used when
370 : analyzing a scalar evolution, instantiating a CHREC or
371 : resolving mixers. */
372 :
373 : class instantiate_cache_type
374 : {
375 : public:
376 : htab_t map;
377 : vec<scev_info_str> entries;
378 :
379 129768808 : instantiate_cache_type () : map (NULL), entries (vNULL) {}
380 : ~instantiate_cache_type ();
381 126578016 : tree get (unsigned slot) { return entries[slot].chrec; }
382 98078904 : void set (unsigned slot, tree chrec) { entries[slot].chrec = chrec; }
383 : };
384 :
385 129768808 : instantiate_cache_type::~instantiate_cache_type ()
386 : {
387 129768808 : if (map != NULL)
388 : {
389 29076953 : htab_delete (map);
390 29076953 : entries.release ();
391 : }
392 129768808 : }
393 :
394 : /* Cache to avoid infinite recursion when instantiating an SSA name.
395 : Live during the outermost analyze_scalar_evolution, instantiate_scev
396 : or resolve_mixers call. */
397 : static instantiate_cache_type *global_cache;
398 :
399 :
400 : /* Return true when PHI is a loop-phi-node. */
401 :
402 : static bool
403 25901913 : loop_phi_node_p (gimple *phi)
404 : {
405 : /* The implementation of this function is based on the following
406 : property: "all the loop-phi-nodes of a loop are contained in the
407 : loop's header basic block". */
408 :
409 0 : return loop_containing_stmt (phi)->header == gimple_bb (phi);
410 : }
411 :
412 : /* Compute the scalar evolution for EVOLUTION_FN after crossing LOOP.
413 : In general, in the case of multivariate evolutions we want to get
414 : the evolution in different loops. LOOP specifies the level for
415 : which to get the evolution.
416 :
417 : Example:
418 :
419 : | for (j = 0; j < 100; j++)
420 : | {
421 : | for (k = 0; k < 100; k++)
422 : | {
423 : | i = k + j; - Here the value of i is a function of j, k.
424 : | }
425 : | ... = i - Here the value of i is a function of j.
426 : | }
427 : | ... = i - Here the value of i is a scalar.
428 :
429 : Example:
430 :
431 : | i_0 = ...
432 : | loop_1 10 times
433 : | i_1 = phi (i_0, i_2)
434 : | i_2 = i_1 + 2
435 : | endloop
436 :
437 : This loop has the same effect as:
438 : LOOP_1 has the same effect as:
439 :
440 : | i_1 = i_0 + 20
441 :
442 : The overall effect of the loop, "i_0 + 20" in the previous example,
443 : is obtained by passing in the parameters: LOOP = 1,
444 : EVOLUTION_FN = {i_0, +, 2}_1.
445 : */
446 :
447 : tree
448 5733563 : compute_overall_effect_of_inner_loop (class loop *loop, tree evolution_fn)
449 : {
450 6627041 : bool val = false;
451 :
452 6627041 : if (evolution_fn == chrec_dont_know)
453 : return chrec_dont_know;
454 :
455 6507748 : else if (TREE_CODE (evolution_fn) == POLYNOMIAL_CHREC)
456 : {
457 2475444 : class loop *inner_loop = get_chrec_loop (evolution_fn);
458 :
459 2475444 : if (inner_loop == loop
460 2475444 : || flow_loop_nested_p (loop, inner_loop))
461 : {
462 2475444 : tree nb_iter = number_of_latch_executions (inner_loop);
463 :
464 2475444 : if (nb_iter == chrec_dont_know)
465 : return chrec_dont_know;
466 : else
467 : {
468 893478 : tree res;
469 :
470 : /* evolution_fn is the evolution function in LOOP. Get
471 : its value in the nb_iter-th iteration. */
472 893478 : res = chrec_apply (inner_loop->num, evolution_fn, nb_iter);
473 :
474 893478 : if (chrec_contains_symbols_defined_in_loop (res, loop->num))
475 61568 : res = instantiate_parameters (loop, res);
476 :
477 : /* Continue the computation until ending on a parent of LOOP. */
478 893478 : return compute_overall_effect_of_inner_loop (loop, res);
479 : }
480 : }
481 : else
482 : return evolution_fn;
483 : }
484 :
485 : /* If the evolution function is an invariant, there is nothing to do. */
486 4032304 : else if (no_evolution_in_loop_p (evolution_fn, loop->num, &val) && val)
487 : return evolution_fn;
488 :
489 : else
490 3252007 : return chrec_dont_know;
491 : }
492 :
493 : /* Associate CHREC to SCALAR. */
494 :
495 : static void
496 49801109 : set_scalar_evolution (basic_block instantiated_below, tree scalar, tree chrec)
497 : {
498 49801109 : tree *scalar_info;
499 :
500 49801109 : if (TREE_CODE (scalar) != SSA_NAME)
501 : return;
502 :
503 49801109 : scalar_info = find_var_scev_info (instantiated_below, scalar);
504 :
505 49801109 : if (dump_file)
506 : {
507 84477 : if (dump_flags & TDF_SCEV)
508 : {
509 11 : fprintf (dump_file, "(set_scalar_evolution \n");
510 11 : fprintf (dump_file, " instantiated_below = %d \n",
511 : instantiated_below->index);
512 11 : fprintf (dump_file, " (scalar = ");
513 11 : print_generic_expr (dump_file, scalar);
514 11 : fprintf (dump_file, ")\n (scalar_evolution = ");
515 11 : print_generic_expr (dump_file, chrec);
516 11 : fprintf (dump_file, "))\n");
517 : }
518 84477 : if (dump_flags & TDF_STATS)
519 7216 : nb_set_scev++;
520 : }
521 :
522 49801109 : *scalar_info = chrec;
523 : }
524 :
525 : /* Retrieve the chrec associated to SCALAR instantiated below
526 : INSTANTIATED_BELOW block. */
527 :
528 : static tree
529 193733911 : get_scalar_evolution (basic_block instantiated_below, tree scalar)
530 : {
531 193733911 : tree res;
532 :
533 193733911 : if (dump_file)
534 : {
535 691875 : if (dump_flags & TDF_SCEV)
536 : {
537 36 : fprintf (dump_file, "(get_scalar_evolution \n");
538 36 : fprintf (dump_file, " (scalar = ");
539 36 : print_generic_expr (dump_file, scalar);
540 36 : fprintf (dump_file, ")\n");
541 : }
542 691875 : if (dump_flags & TDF_STATS)
543 50926 : nb_get_scev++;
544 : }
545 :
546 193733911 : if (VECTOR_TYPE_P (TREE_TYPE (scalar))
547 193733911 : || TREE_CODE (TREE_TYPE (scalar)) == COMPLEX_TYPE)
548 : /* For chrec_dont_know we keep the symbolic form. */
549 : res = scalar;
550 : else
551 193431488 : switch (TREE_CODE (scalar))
552 : {
553 158036420 : case SSA_NAME:
554 158036420 : if (SSA_NAME_IS_DEFAULT_DEF (scalar))
555 : res = scalar;
556 : else
557 155954663 : res = *find_var_scev_info (instantiated_below, scalar);
558 : break;
559 :
560 : case REAL_CST:
561 : case FIXED_CST:
562 : case INTEGER_CST:
563 : res = scalar;
564 : break;
565 :
566 : default:
567 193733911 : res = chrec_not_analyzed_yet;
568 : break;
569 : }
570 :
571 193733911 : if (dump_file && (dump_flags & TDF_SCEV))
572 : {
573 36 : fprintf (dump_file, " (scalar_evolution = ");
574 36 : print_generic_expr (dump_file, res);
575 36 : fprintf (dump_file, "))\n");
576 : }
577 :
578 193733911 : return res;
579 : }
580 :
581 :
582 : /* Depth first search algorithm. */
583 :
584 : enum t_bool {
585 : t_false,
586 : t_true,
587 : t_dont_know
588 : };
589 :
590 : class scev_dfs
591 : {
592 : public:
593 10737717 : scev_dfs (class loop *loop_, gphi *phi_, tree init_cond_)
594 10737717 : : loop (loop_), loop_phi_node (phi_), init_cond (init_cond_) {}
595 : t_bool get_ev (tree *, tree);
596 :
597 : private:
598 : t_bool follow_ssa_edge_expr (gimple *, tree, tree *, int);
599 : t_bool follow_ssa_edge_binary (gimple *at_stmt,
600 : tree type, tree rhs0, enum tree_code code,
601 : tree rhs1, tree *evolution_of_loop, int limit);
602 : t_bool follow_ssa_edge_in_condition_phi_branch (int i,
603 : gphi *condition_phi,
604 : tree *evolution_of_branch,
605 : tree init_cond, int limit);
606 : t_bool follow_ssa_edge_in_condition_phi (gphi *condition_phi,
607 : tree *evolution_of_loop, int limit);
608 : t_bool follow_ssa_edge_inner_loop_phi (gphi *loop_phi_node,
609 : tree *evolution_of_loop, int limit);
610 : tree add_to_evolution (tree chrec_before, enum tree_code code,
611 : tree to_add, gimple *at_stmt);
612 : tree add_to_evolution_1 (tree chrec_before, tree to_add, gimple *at_stmt);
613 :
614 : class loop *loop;
615 : gphi *loop_phi_node;
616 : tree init_cond;
617 : };
618 :
619 : t_bool
620 10737717 : scev_dfs::get_ev (tree *ev_fn, tree arg)
621 : {
622 10737717 : *ev_fn = chrec_dont_know;
623 10737717 : return follow_ssa_edge_expr (loop_phi_node, arg, ev_fn, 0);
624 : }
625 :
626 : /* Helper function for add_to_evolution. Returns the evolution
627 : function for an assignment of the form "a = b + c", where "a" and
628 : "b" are on the strongly connected component. CHREC_BEFORE is the
629 : information that we already have collected up to this point.
630 : TO_ADD is the evolution of "c".
631 :
632 : When CHREC_BEFORE has an evolution part in LOOP_NB, add to this
633 : evolution the expression TO_ADD, otherwise construct an evolution
634 : part for this loop. */
635 :
636 : tree
637 8902707 : scev_dfs::add_to_evolution_1 (tree chrec_before, tree to_add, gimple *at_stmt)
638 : {
639 8902707 : tree type, left, right;
640 8902707 : unsigned loop_nb = loop->num;
641 8902707 : class loop *chloop;
642 :
643 8902707 : switch (TREE_CODE (chrec_before))
644 : {
645 159321 : case POLYNOMIAL_CHREC:
646 159321 : chloop = get_chrec_loop (chrec_before);
647 159321 : if (chloop == loop
648 159321 : || flow_loop_nested_p (chloop, loop))
649 : {
650 159321 : unsigned var;
651 :
652 159321 : type = chrec_type (chrec_before);
653 :
654 : /* When there is no evolution part in this loop, build it. */
655 159321 : if (chloop != loop)
656 : {
657 0 : var = loop_nb;
658 0 : left = chrec_before;
659 0 : right = SCALAR_FLOAT_TYPE_P (type)
660 0 : ? build_real (type, dconst0)
661 0 : : build_int_cst (type, 0);
662 : }
663 : else
664 : {
665 159321 : var = CHREC_VARIABLE (chrec_before);
666 159321 : left = CHREC_LEFT (chrec_before);
667 159321 : right = CHREC_RIGHT (chrec_before);
668 : }
669 :
670 159321 : to_add = chrec_convert (type, to_add, at_stmt);
671 159321 : right = chrec_convert_rhs (type, right, at_stmt);
672 159321 : right = chrec_fold_plus (chrec_type (right), right, to_add);
673 : /* When we have an evolution in a non-wrapping type and
674 : in the process of accumulating CHREC_RIGHT there was
675 : overflow this indicates in the association that happened
676 : in building the CHREC clearly involved UB. Avoid this.
677 : In building a CHREC we basically turn (a + INCR1) + INCR2
678 : into a + (INCR1 + INCR2) which is not always valid.
679 : Note this check only catches few invalid cases. */
680 80191 : if ((INTEGRAL_TYPE_P (type) && ! TYPE_OVERFLOW_WRAPS (type))
681 41615 : && TREE_CODE (right) == INTEGER_CST
682 168472 : && TREE_OVERFLOW (right))
683 5 : return chrec_dont_know;
684 159316 : return build_polynomial_chrec (var, left, right);
685 : }
686 : else
687 : {
688 0 : gcc_assert (flow_loop_nested_p (loop, chloop));
689 :
690 : /* Search the evolution in LOOP_NB. */
691 0 : left = add_to_evolution_1 (CHREC_LEFT (chrec_before),
692 : to_add, at_stmt);
693 0 : right = CHREC_RIGHT (chrec_before);
694 0 : right = chrec_convert_rhs (chrec_type (left), right, at_stmt);
695 0 : return build_polynomial_chrec (CHREC_VARIABLE (chrec_before),
696 0 : left, right);
697 : }
698 :
699 8743386 : default:
700 : /* These nodes do not depend on a loop. */
701 8743386 : if (chrec_before == chrec_dont_know)
702 : return chrec_dont_know;
703 :
704 8724404 : left = chrec_before;
705 8724404 : right = chrec_convert_rhs (chrec_type (left), to_add, at_stmt);
706 : /* When we add the first evolution we need to replace the symbolic
707 : evolution we've put in when the DFS reached the loop PHI node
708 : with the initial value. There's only a limited cases of
709 : extra operations ontop of that symbol allowed, namely
710 : sign-conversions we can look through. For other cases we leave
711 : the symbolic initial condition which causes build_polynomial_chrec
712 : to return chrec_dont_know. See PR42512, PR66375 and PR107176 for
713 : cases we mishandled before. */
714 8724404 : STRIP_NOPS (chrec_before);
715 8724404 : if (chrec_before == gimple_phi_result (loop_phi_node))
716 8723683 : left = fold_convert (TREE_TYPE (left), init_cond);
717 8724404 : return build_polynomial_chrec (loop_nb, left, right);
718 : }
719 : }
720 :
721 : /* Add TO_ADD to the evolution part of CHREC_BEFORE in the dimension
722 : of LOOP_NB.
723 :
724 : Description (provided for completeness, for those who read code in
725 : a plane, and for my poor 62 bytes brain that would have forgotten
726 : all this in the next two or three months):
727 :
728 : The algorithm of translation of programs from the SSA representation
729 : into the chrecs syntax is based on a pattern matching. After having
730 : reconstructed the overall tree expression for a loop, there are only
731 : two cases that can arise:
732 :
733 : 1. a = loop-phi (init, a + expr)
734 : 2. a = loop-phi (init, expr)
735 :
736 : where EXPR is either a scalar constant with respect to the analyzed
737 : loop (this is a degree 0 polynomial), or an expression containing
738 : other loop-phi definitions (these are higher degree polynomials).
739 :
740 : Examples:
741 :
742 : 1.
743 : | init = ...
744 : | loop_1
745 : | a = phi (init, a + 5)
746 : | endloop
747 :
748 : 2.
749 : | inita = ...
750 : | initb = ...
751 : | loop_1
752 : | a = phi (inita, 2 * b + 3)
753 : | b = phi (initb, b + 1)
754 : | endloop
755 :
756 : For the first case, the semantics of the SSA representation is:
757 :
758 : | a (x) = init + \sum_{j = 0}^{x - 1} expr (j)
759 :
760 : that is, there is a loop index "x" that determines the scalar value
761 : of the variable during the loop execution. During the first
762 : iteration, the value is that of the initial condition INIT, while
763 : during the subsequent iterations, it is the sum of the initial
764 : condition with the sum of all the values of EXPR from the initial
765 : iteration to the before last considered iteration.
766 :
767 : For the second case, the semantics of the SSA program is:
768 :
769 : | a (x) = init, if x = 0;
770 : | expr (x - 1), otherwise.
771 :
772 : The second case corresponds to the PEELED_CHREC, whose syntax is
773 : close to the syntax of a loop-phi-node:
774 :
775 : | phi (init, expr) vs. (init, expr)_x
776 :
777 : The proof of the translation algorithm for the first case is a
778 : proof by structural induction based on the degree of EXPR.
779 :
780 : Degree 0:
781 : When EXPR is a constant with respect to the analyzed loop, or in
782 : other words when EXPR is a polynomial of degree 0, the evolution of
783 : the variable A in the loop is an affine function with an initial
784 : condition INIT, and a step EXPR. In order to show this, we start
785 : from the semantics of the SSA representation:
786 :
787 : f (x) = init + \sum_{j = 0}^{x - 1} expr (j)
788 :
789 : and since "expr (j)" is a constant with respect to "j",
790 :
791 : f (x) = init + x * expr
792 :
793 : Finally, based on the semantics of the pure sum chrecs, by
794 : identification we get the corresponding chrecs syntax:
795 :
796 : f (x) = init * \binom{x}{0} + expr * \binom{x}{1}
797 : f (x) -> {init, +, expr}_x
798 :
799 : Higher degree:
800 : Suppose that EXPR is a polynomial of degree N with respect to the
801 : analyzed loop_x for which we have already determined that it is
802 : written under the chrecs syntax:
803 :
804 : | expr (x) -> {b_0, +, b_1, +, ..., +, b_{n-1}} (x)
805 :
806 : We start from the semantics of the SSA program:
807 :
808 : | f (x) = init + \sum_{j = 0}^{x - 1} expr (j)
809 : |
810 : | f (x) = init + \sum_{j = 0}^{x - 1}
811 : | (b_0 * \binom{j}{0} + ... + b_{n-1} * \binom{j}{n-1})
812 : |
813 : | f (x) = init + \sum_{j = 0}^{x - 1}
814 : | \sum_{k = 0}^{n - 1} (b_k * \binom{j}{k})
815 : |
816 : | f (x) = init + \sum_{k = 0}^{n - 1}
817 : | (b_k * \sum_{j = 0}^{x - 1} \binom{j}{k})
818 : |
819 : | f (x) = init + \sum_{k = 0}^{n - 1}
820 : | (b_k * \binom{x}{k + 1})
821 : |
822 : | f (x) = init + b_0 * \binom{x}{1} + ...
823 : | + b_{n-1} * \binom{x}{n}
824 : |
825 : | f (x) = init * \binom{x}{0} + b_0 * \binom{x}{1} + ...
826 : | + b_{n-1} * \binom{x}{n}
827 : |
828 :
829 : And finally from the definition of the chrecs syntax, we identify:
830 : | f (x) -> {init, +, b_0, +, ..., +, b_{n-1}}_x
831 :
832 : This shows the mechanism that stands behind the add_to_evolution
833 : function. An important point is that the use of symbolic
834 : parameters avoids the need of an analysis schedule.
835 :
836 : Example:
837 :
838 : | inita = ...
839 : | initb = ...
840 : | loop_1
841 : | a = phi (inita, a + 2 + b)
842 : | b = phi (initb, b + 1)
843 : | endloop
844 :
845 : When analyzing "a", the algorithm keeps "b" symbolically:
846 :
847 : | a -> {inita, +, 2 + b}_1
848 :
849 : Then, after instantiation, the analyzer ends on the evolution:
850 :
851 : | a -> {inita, +, 2 + initb, +, 1}_1
852 :
853 : */
854 :
855 : tree
856 8902707 : scev_dfs::add_to_evolution (tree chrec_before, enum tree_code code,
857 : tree to_add, gimple *at_stmt)
858 : {
859 8902707 : tree type = chrec_type (to_add);
860 8902707 : tree res = NULL_TREE;
861 :
862 8902707 : if (to_add == NULL_TREE)
863 : return chrec_before;
864 :
865 : /* TO_ADD is either a scalar, or a parameter. TO_ADD is not
866 : instantiated at this point. */
867 8902707 : if (TREE_CODE (to_add) == POLYNOMIAL_CHREC)
868 : /* This should not happen. */
869 0 : return chrec_dont_know;
870 :
871 8902707 : if (dump_file && (dump_flags & TDF_SCEV))
872 : {
873 1 : fprintf (dump_file, "(add_to_evolution \n");
874 1 : fprintf (dump_file, " (loop_nb = %d)\n", loop->num);
875 1 : fprintf (dump_file, " (chrec_before = ");
876 1 : print_generic_expr (dump_file, chrec_before);
877 1 : fprintf (dump_file, ")\n (to_add = ");
878 1 : print_generic_expr (dump_file, to_add);
879 1 : fprintf (dump_file, ")\n");
880 : }
881 :
882 8902707 : if (code == MINUS_EXPR)
883 : {
884 1602454 : if (INTEGRAL_TYPE_P (type)
885 796594 : && TYPE_OVERFLOW_UNDEFINED (type)
886 868563 : && !expr_not_equal_to (to_add,
887 868563 : wi::to_wide (TYPE_MIN_VALUE (type))))
888 : {
889 38021 : tree utype = unsigned_type_for (type);
890 38021 : to_add = chrec_convert_rhs (utype, to_add);
891 38021 : to_add = chrec_fold_multiply (utype, to_add,
892 : build_int_cst_type (utype, -1));
893 38021 : to_add = chrec_convert_rhs (type, to_add);
894 : }
895 : else
896 1526412 : to_add = chrec_fold_multiply (type, to_add, SCALAR_FLOAT_TYPE_P (type)
897 4633 : ? build_real (type, dconstm1)
898 1521779 : : build_int_cst_type (type, -1));
899 : }
900 :
901 8902707 : res = add_to_evolution_1 (chrec_before, to_add, at_stmt);
902 :
903 8902707 : if (dump_file && (dump_flags & TDF_SCEV))
904 : {
905 1 : fprintf (dump_file, " (res = ");
906 1 : print_generic_expr (dump_file, res);
907 1 : fprintf (dump_file, "))\n");
908 : }
909 :
910 : return res;
911 : }
912 :
913 :
914 : /* Follow the ssa edge into the binary expression RHS0 CODE RHS1.
915 : Return true if the strongly connected component has been found. */
916 :
917 : t_bool
918 1075240 : scev_dfs::follow_ssa_edge_binary (gimple *at_stmt, tree type, tree rhs0,
919 : enum tree_code code, tree rhs1,
920 : tree *evolution_of_loop, int limit)
921 : {
922 1075240 : t_bool res = t_false;
923 1075240 : tree evol;
924 :
925 1075240 : switch (code)
926 : {
927 1069121 : case POINTER_PLUS_EXPR:
928 1069121 : case PLUS_EXPR:
929 1069121 : if (TREE_CODE (rhs0) == SSA_NAME)
930 : {
931 1052320 : if (TREE_CODE (rhs1) == SSA_NAME)
932 : {
933 : /* Match an assignment under the form:
934 : "a = b + c". */
935 :
936 : /* We want only assignments of form "name + name" contribute to
937 : LIMIT, as the other cases do not necessarily contribute to
938 : the complexity of the expression. */
939 1052320 : limit++;
940 :
941 1052320 : evol = *evolution_of_loop;
942 1052320 : res = follow_ssa_edge_expr (at_stmt, rhs0, &evol, limit);
943 1052320 : if (res == t_true)
944 427077 : *evolution_of_loop = add_to_evolution
945 427077 : (chrec_convert (type, evol, at_stmt), code, rhs1, at_stmt);
946 625243 : else if (res == t_false)
947 : {
948 607382 : res = follow_ssa_edge_expr
949 607382 : (at_stmt, rhs1, evolution_of_loop, limit);
950 607382 : if (res == t_true)
951 458245 : *evolution_of_loop = add_to_evolution
952 458245 : (chrec_convert (type, *evolution_of_loop, at_stmt),
953 : code, rhs0, at_stmt);
954 : }
955 : }
956 :
957 : else
958 0 : gcc_unreachable (); /* Handled in caller. */
959 : }
960 :
961 16801 : else if (TREE_CODE (rhs1) == SSA_NAME)
962 : {
963 : /* Match an assignment under the form:
964 : "a = ... + c". */
965 5675 : res = follow_ssa_edge_expr (at_stmt, rhs1, evolution_of_loop, limit);
966 5675 : if (res == t_true)
967 5036 : *evolution_of_loop = add_to_evolution
968 5036 : (chrec_convert (type, *evolution_of_loop, at_stmt),
969 : code, rhs0, at_stmt);
970 : }
971 :
972 : else
973 : /* Otherwise, match an assignment under the form:
974 : "a = ... + ...". */
975 : /* And there is nothing to do. */
976 : res = t_false;
977 : break;
978 :
979 6119 : case MINUS_EXPR:
980 : /* This case is under the form "opnd0 = rhs0 - rhs1". */
981 6119 : if (TREE_CODE (rhs0) == SSA_NAME)
982 0 : gcc_unreachable (); /* Handled in caller. */
983 : else
984 : /* Otherwise, match an assignment under the form:
985 : "a = ... - ...". */
986 : /* And there is nothing to do. */
987 : res = t_false;
988 : break;
989 :
990 : default:
991 : res = t_false;
992 : }
993 :
994 1075240 : return res;
995 : }
996 :
997 : /* Checks whether the I-th argument of a PHI comes from a backedge. */
998 :
999 : static bool
1000 8372810 : backedge_phi_arg_p (gphi *phi, int i)
1001 : {
1002 8372810 : const_edge e = gimple_phi_arg_edge (phi, i);
1003 :
1004 : /* We would in fact like to test EDGE_DFS_BACK here, but we do not care
1005 : about updating it anywhere, and this should work as well most of the
1006 : time. */
1007 8372810 : if (e->flags & EDGE_IRREDUCIBLE_LOOP)
1008 47229 : return true;
1009 :
1010 : return false;
1011 : }
1012 :
1013 : /* Helper function for one branch of the condition-phi-node. Return
1014 : true if the strongly connected component has been found following
1015 : this path. */
1016 :
1017 : t_bool
1018 3416727 : scev_dfs::follow_ssa_edge_in_condition_phi_branch (int i,
1019 : gphi *condition_phi,
1020 : tree *evolution_of_branch,
1021 : tree init_cond, int limit)
1022 : {
1023 3416727 : tree branch = PHI_ARG_DEF (condition_phi, i);
1024 3416727 : *evolution_of_branch = chrec_dont_know;
1025 :
1026 : /* Do not follow back edges (they must belong to an irreducible loop, which
1027 : we really do not want to worry about). */
1028 3416727 : if (backedge_phi_arg_p (condition_phi, i))
1029 : return t_false;
1030 :
1031 3411110 : if (TREE_CODE (branch) == SSA_NAME)
1032 : {
1033 3177574 : *evolution_of_branch = init_cond;
1034 3177574 : return follow_ssa_edge_expr (condition_phi, branch,
1035 3177574 : evolution_of_branch, limit);
1036 : }
1037 :
1038 : /* This case occurs when one of the condition branches sets
1039 : the variable to a constant: i.e. a phi-node like
1040 : "a_2 = PHI <a_7(5), 2(6)>;".
1041 :
1042 : FIXME: This case have to be refined correctly:
1043 : in some cases it is possible to say something better than
1044 : chrec_dont_know, for example using a wrap-around notation. */
1045 : return t_false;
1046 : }
1047 :
1048 : /* This function merges the branches of a condition-phi-node in a
1049 : loop. */
1050 :
1051 : t_bool
1052 2195126 : scev_dfs::follow_ssa_edge_in_condition_phi (gphi *condition_phi,
1053 : tree *evolution_of_loop, int limit)
1054 : {
1055 2195126 : int i, n;
1056 2195126 : tree init = *evolution_of_loop;
1057 2195126 : tree evolution_of_branch;
1058 2195126 : t_bool res = follow_ssa_edge_in_condition_phi_branch (0, condition_phi,
1059 : &evolution_of_branch,
1060 : init, limit);
1061 2195126 : if (res == t_false || res == t_dont_know)
1062 : return res;
1063 :
1064 1260991 : *evolution_of_loop = evolution_of_branch;
1065 :
1066 1260991 : n = gimple_phi_num_args (condition_phi);
1067 1798190 : for (i = 1; i < n; i++)
1068 : {
1069 : /* Quickly give up when the evolution of one of the branches is
1070 : not known. */
1071 1360143 : if (*evolution_of_loop == chrec_dont_know)
1072 : return t_true;
1073 :
1074 : /* Increase the limit by the PHI argument number to avoid exponential
1075 : time and memory complexity. */
1076 1221601 : res = follow_ssa_edge_in_condition_phi_branch (i, condition_phi,
1077 : &evolution_of_branch,
1078 : init, limit + i);
1079 1221601 : if (res == t_false || res == t_dont_know)
1080 : return res;
1081 :
1082 537199 : *evolution_of_loop = chrec_merge (*evolution_of_loop,
1083 : evolution_of_branch);
1084 : }
1085 :
1086 : return t_true;
1087 : }
1088 :
1089 : /* Follow an SSA edge in an inner loop. It computes the overall
1090 : effect of the loop, and following the symbolic initial conditions,
1091 : it follows the edges in the parent loop. The inner loop is
1092 : considered as a single statement. */
1093 :
1094 : t_bool
1095 251444 : scev_dfs::follow_ssa_edge_inner_loop_phi (gphi *loop_phi_node,
1096 : tree *evolution_of_loop, int limit)
1097 : {
1098 251444 : class loop *loop = loop_containing_stmt (loop_phi_node);
1099 251444 : tree ev = analyze_scalar_evolution (loop, PHI_RESULT (loop_phi_node));
1100 :
1101 : /* Sometimes, the inner loop is too difficult to analyze, and the
1102 : result of the analysis is a symbolic parameter. */
1103 251444 : if (ev == PHI_RESULT (loop_phi_node))
1104 : {
1105 97272 : t_bool res = t_false;
1106 97272 : int i, n = gimple_phi_num_args (loop_phi_node);
1107 :
1108 144598 : for (i = 0; i < n; i++)
1109 : {
1110 136595 : tree arg = PHI_ARG_DEF (loop_phi_node, i);
1111 136595 : basic_block bb;
1112 :
1113 : /* Follow the edges that exit the inner loop. */
1114 136595 : bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
1115 136595 : if (!flow_bb_inside_loop_p (loop, bb))
1116 97272 : res = follow_ssa_edge_expr (loop_phi_node,
1117 : arg, evolution_of_loop, limit);
1118 136595 : if (res == t_true)
1119 : break;
1120 : }
1121 :
1122 : /* If the path crosses this loop-phi, give up. */
1123 97272 : if (res == t_true)
1124 89269 : *evolution_of_loop = chrec_dont_know;
1125 :
1126 97272 : return res;
1127 : }
1128 :
1129 : /* Otherwise, compute the overall effect of the inner loop. */
1130 154172 : ev = compute_overall_effect_of_inner_loop (loop, ev);
1131 154172 : return follow_ssa_edge_expr (loop_phi_node, ev, evolution_of_loop, limit);
1132 : }
1133 :
1134 : /* Follow the ssa edge into the expression EXPR.
1135 : Return true if the strongly connected component has been found. */
1136 :
1137 : t_bool
1138 24328252 : scev_dfs::follow_ssa_edge_expr (gimple *at_stmt, tree expr,
1139 : tree *evolution_of_loop, int limit)
1140 : {
1141 24328252 : gphi *halting_phi = loop_phi_node;
1142 24328252 : enum tree_code code;
1143 24328252 : tree type, rhs0, rhs1 = NULL_TREE;
1144 :
1145 : /* The EXPR is one of the following cases:
1146 : - an SSA_NAME,
1147 : - an INTEGER_CST,
1148 : - a PLUS_EXPR,
1149 : - a POINTER_PLUS_EXPR,
1150 : - a MINUS_EXPR,
1151 : - other cases are not yet handled. */
1152 :
1153 : /* For SSA_NAME look at the definition statement, handling
1154 : PHI nodes and otherwise expand appropriately for the expression
1155 : handling below. */
1156 24328252 : if (TREE_CODE (expr) == SSA_NAME)
1157 : {
1158 24161981 : gimple *def = SSA_NAME_DEF_STMT (expr);
1159 :
1160 24161981 : if (gimple_nop_p (def))
1161 : return t_false;
1162 :
1163 : /* Give up if the path is longer than the MAX that we allow. */
1164 24145999 : if (limit > param_scev_max_expr_complexity)
1165 : {
1166 6160 : *evolution_of_loop = chrec_dont_know;
1167 6160 : return t_dont_know;
1168 : }
1169 :
1170 24139839 : if (gphi *phi = dyn_cast <gphi *>(def))
1171 : {
1172 24878184 : if (!loop_phi_node_p (phi))
1173 : /* DEF is a condition-phi-node. Follow the branches, and
1174 : record their evolutions. Finally, merge the collected
1175 : information and set the approximation to the main
1176 : variable. */
1177 2195126 : return follow_ssa_edge_in_condition_phi (phi, evolution_of_loop,
1178 2195126 : limit);
1179 :
1180 : /* When the analyzed phi is the halting_phi, the
1181 : depth-first search is over: we have found a path from
1182 : the halting_phi to itself in the loop. */
1183 10243966 : if (phi == halting_phi)
1184 : {
1185 9781151 : *evolution_of_loop = expr;
1186 9781151 : return t_true;
1187 : }
1188 :
1189 : /* Otherwise, the evolution of the HALTING_PHI depends
1190 : on the evolution of another loop-phi-node, i.e. the
1191 : evolution function is a higher degree polynomial. */
1192 462815 : class loop *def_loop = loop_containing_stmt (def);
1193 462815 : if (def_loop == loop)
1194 : return t_false;
1195 :
1196 : /* Inner loop. */
1197 272838 : if (flow_loop_nested_p (loop, def_loop))
1198 251444 : return follow_ssa_edge_inner_loop_phi (phi, evolution_of_loop,
1199 251444 : limit + 1);
1200 :
1201 : /* Outer loop. */
1202 : return t_false;
1203 : }
1204 :
1205 : /* At this level of abstraction, the program is just a set
1206 : of GIMPLE_ASSIGNs and PHI_NODEs. In principle there is no
1207 : other def to be handled. */
1208 11700747 : if (!is_gimple_assign (def))
1209 : return t_false;
1210 :
1211 11591889 : code = gimple_assign_rhs_code (def);
1212 11591889 : switch (get_gimple_rhs_class (code))
1213 : {
1214 10074016 : case GIMPLE_BINARY_RHS:
1215 10074016 : rhs0 = gimple_assign_rhs1 (def);
1216 10074016 : rhs1 = gimple_assign_rhs2 (def);
1217 10074016 : break;
1218 1486708 : case GIMPLE_UNARY_RHS:
1219 1486708 : case GIMPLE_SINGLE_RHS:
1220 1486708 : rhs0 = gimple_assign_rhs1 (def);
1221 1486708 : break;
1222 : default:
1223 : return t_false;
1224 : }
1225 11560724 : type = TREE_TYPE (gimple_assign_lhs (def));
1226 11560724 : at_stmt = def;
1227 : }
1228 : else
1229 : {
1230 166271 : code = TREE_CODE (expr);
1231 166271 : type = TREE_TYPE (expr);
1232 : /* Via follow_ssa_edge_inner_loop_phi we arrive here with the
1233 : GENERIC scalar evolution of the inner loop. */
1234 166271 : switch (code)
1235 : {
1236 10732 : CASE_CONVERT:
1237 10732 : rhs0 = TREE_OPERAND (expr, 0);
1238 10732 : break;
1239 22477 : case POINTER_PLUS_EXPR:
1240 22477 : case PLUS_EXPR:
1241 22477 : case MINUS_EXPR:
1242 22477 : rhs0 = TREE_OPERAND (expr, 0);
1243 22477 : rhs1 = TREE_OPERAND (expr, 1);
1244 22477 : STRIP_USELESS_TYPE_CONVERSION (rhs0);
1245 22477 : STRIP_USELESS_TYPE_CONVERSION (rhs1);
1246 22477 : break;
1247 : default:
1248 : rhs0 = expr;
1249 : }
1250 : }
1251 :
1252 11726995 : switch (code)
1253 : {
1254 359825 : CASE_CONVERT:
1255 359825 : {
1256 : /* This assignment is under the form "a_1 = (cast) rhs. We cannot
1257 : validate any precision altering conversion during the SCC
1258 : analysis, so don't even try. */
1259 359825 : if (!tree_nop_conversion_p (type, TREE_TYPE (rhs0)))
1260 : return t_false;
1261 245779 : t_bool res = follow_ssa_edge_expr (at_stmt, rhs0,
1262 : evolution_of_loop, limit);
1263 245779 : if (res == t_true)
1264 99787 : *evolution_of_loop = chrec_convert (type, *evolution_of_loop,
1265 : at_stmt);
1266 : return res;
1267 : }
1268 :
1269 : case INTEGER_CST:
1270 : /* This assignment is under the form "a_1 = 7". */
1271 : return t_false;
1272 :
1273 2201 : case ADDR_EXPR:
1274 2201 : {
1275 : /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR. */
1276 2201 : if (TREE_CODE (TREE_OPERAND (rhs0, 0)) != MEM_REF)
1277 : return t_false;
1278 1 : tree mem = TREE_OPERAND (rhs0, 0);
1279 1 : rhs0 = TREE_OPERAND (mem, 0);
1280 1 : rhs1 = TREE_OPERAND (mem, 1);
1281 1 : code = POINTER_PLUS_EXPR;
1282 : }
1283 : /* Fallthru. */
1284 9325601 : case POINTER_PLUS_EXPR:
1285 9325601 : case PLUS_EXPR:
1286 9325601 : case MINUS_EXPR:
1287 : /* This case is under the form "rhs0 +- rhs1". */
1288 9325601 : if (TREE_CODE (rhs0) == SSA_NAME
1289 9302681 : && (TREE_CODE (rhs1) != SSA_NAME || code == MINUS_EXPR))
1290 : {
1291 : /* Match an assignment under the form:
1292 : "a = b +- ...". */
1293 8250361 : t_bool res = follow_ssa_edge_expr (at_stmt, rhs0,
1294 : evolution_of_loop, limit);
1295 8250361 : if (res == t_true)
1296 8012349 : *evolution_of_loop = add_to_evolution
1297 8012349 : (chrec_convert (type, *evolution_of_loop, at_stmt),
1298 : code, rhs1, at_stmt);
1299 8250361 : return res;
1300 : }
1301 : /* Else search for the SCC in both rhs0 and rhs1. */
1302 1075240 : return follow_ssa_edge_binary (at_stmt, type, rhs0, code, rhs1,
1303 1075240 : evolution_of_loop, limit);
1304 :
1305 : default:
1306 : return t_false;
1307 : }
1308 : }
1309 :
1310 :
1311 : /* This section selects the loops that will be good candidates for the
1312 : scalar evolution analysis. For the moment, greedily select all the
1313 : loop nests we could analyze. */
1314 :
1315 : /* For a loop with a single exit edge, return the COND_EXPR that
1316 : guards the exit edge. If the expression is too difficult to
1317 : analyze, then give up. */
1318 :
1319 : gcond *
1320 236 : get_loop_exit_condition (const class loop *loop)
1321 : {
1322 236 : return get_loop_exit_condition (single_exit (loop));
1323 : }
1324 :
1325 : /* If the statement just before the EXIT_EDGE contains a condition then
1326 : return the condition, otherwise NULL. */
1327 :
1328 : gcond *
1329 5077974 : get_loop_exit_condition (const_edge exit_edge)
1330 : {
1331 5077974 : gcond *res = NULL;
1332 :
1333 5077974 : if (dump_file && (dump_flags & TDF_SCEV))
1334 2 : fprintf (dump_file, "(get_loop_exit_condition \n ");
1335 :
1336 5077974 : if (exit_edge)
1337 15233922 : res = safe_dyn_cast <gcond *> (*gsi_last_bb (exit_edge->src));
1338 :
1339 5077974 : if (dump_file && (dump_flags & TDF_SCEV))
1340 : {
1341 2 : print_gimple_stmt (dump_file, res, 0);
1342 2 : fprintf (dump_file, ")\n");
1343 : }
1344 :
1345 5077974 : return res;
1346 : }
1347 :
1348 :
1349 : /* Simplify PEELED_CHREC represented by (init_cond, arg) in LOOP.
1350 : Handle below case and return the corresponding POLYNOMIAL_CHREC:
1351 :
1352 : # i_17 = PHI <i_13(5), 0(3)>
1353 : # _20 = PHI <_5(5), start_4(D)(3)>
1354 : ...
1355 : i_13 = i_17 + 1;
1356 : _5 = start_4(D) + i_13;
1357 :
1358 : Though variable _20 appears as a PEELED_CHREC in the form of
1359 : (start_4, _5)_LOOP, it's a POLYNOMIAL_CHREC like {start_4, 1}_LOOP.
1360 :
1361 : See PR41488. */
1362 :
1363 : static tree
1364 1570935 : simplify_peeled_chrec (class loop *loop, tree arg, tree init_cond)
1365 : {
1366 3141870 : aff_tree aff1, aff2;
1367 1570935 : tree ev, left, right, type, step_val;
1368 1570935 : hash_map<tree, name_expansion *> *peeled_chrec_map = NULL;
1369 :
1370 1570935 : ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, arg));
1371 1570935 : if (ev == NULL_TREE)
1372 0 : return chrec_dont_know;
1373 :
1374 : /* Support the case where we can derive the original CHREC from the
1375 : peeled one if that's a converted other IV. This can be done
1376 : when the original unpeeled converted IV does not overflow and
1377 : has the same initial value. */
1378 1560837 : if (CONVERT_EXPR_P (ev)
1379 10098 : && TREE_CODE (init_cond) == INTEGER_CST
1380 3411 : && TREE_CODE (TREE_OPERAND (ev, 0)) == POLYNOMIAL_CHREC
1381 3142 : && (TYPE_PRECISION (TREE_TYPE (ev))
1382 3142 : > TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (ev, 0))))
1383 1573989 : && (!TYPE_UNSIGNED (TREE_TYPE (ev))
1384 3054 : || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (ev, 0)))))
1385 : {
1386 3054 : left = CHREC_LEFT (TREE_OPERAND (ev, 0));
1387 3054 : right = CHREC_RIGHT (TREE_OPERAND (ev, 0));
1388 3054 : tree left_before = chrec_fold_minus (TREE_TYPE (TREE_OPERAND (ev, 0)),
1389 : left, right);
1390 3054 : if (TREE_CODE (left_before) == INTEGER_CST
1391 3054 : && wi::to_widest (init_cond) == wi::to_widest (left_before)
1392 6108 : && !scev_probably_wraps_p (NULL_TREE, left_before, right, NULL,
1393 : loop, false))
1394 157 : return build_polynomial_chrec (loop->num, init_cond,
1395 157 : chrec_convert (TREE_TYPE (ev),
1396 : right, NULL,
1397 157 : false, NULL_TREE));
1398 2897 : return chrec_dont_know;
1399 : }
1400 :
1401 1567881 : if (TREE_CODE (ev) != POLYNOMIAL_CHREC)
1402 1528117 : return chrec_dont_know;
1403 :
1404 39764 : left = CHREC_LEFT (ev);
1405 39764 : right = CHREC_RIGHT (ev);
1406 39764 : type = TREE_TYPE (left);
1407 39764 : step_val = chrec_fold_plus (type, init_cond, right);
1408 :
1409 : /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP
1410 : if "left" equals to "init + right". */
1411 39764 : if (operand_equal_p (left, step_val, 0))
1412 : {
1413 17773 : if (dump_file && (dump_flags & TDF_SCEV))
1414 1 : fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n");
1415 :
1416 17773 : return build_polynomial_chrec (loop->num, init_cond, right);
1417 : }
1418 :
1419 : /* The affine code only deals with pointer and integer types. */
1420 21991 : if (!POINTER_TYPE_P (type)
1421 16462 : && !INTEGRAL_TYPE_P (type))
1422 15 : return chrec_dont_know;
1423 :
1424 : /* Try harder to check if they are equal. */
1425 21976 : tree_to_aff_combination_expand (left, type, &aff1, &peeled_chrec_map);
1426 21976 : tree_to_aff_combination_expand (step_val, type, &aff2, &peeled_chrec_map);
1427 21976 : free_affine_expand_cache (&peeled_chrec_map);
1428 21976 : aff_combination_scale (&aff2, -1);
1429 21976 : aff_combination_add (&aff1, &aff2);
1430 :
1431 : /* Transform (init, {left, right}_LOOP)_LOOP to {init, right}_LOOP
1432 : if "left" equals to "init + right". */
1433 21976 : if (aff_combination_zero_p (&aff1))
1434 : {
1435 14550 : if (dump_file && (dump_flags & TDF_SCEV))
1436 1 : fprintf (dump_file, "Simplify PEELED_CHREC into POLYNOMIAL_CHREC.\n");
1437 :
1438 14550 : return build_polynomial_chrec (loop->num, init_cond, right);
1439 : }
1440 7426 : return chrec_dont_know;
1441 1570935 : }
1442 :
1443 : /* Given a LOOP_PHI_NODE, this function determines the evolution
1444 : function from LOOP_PHI_NODE to LOOP_PHI_NODE in the loop. */
1445 :
1446 : static tree
1447 10849553 : analyze_evolution_in_loop (gphi *loop_phi_node,
1448 : tree init_cond)
1449 : {
1450 10849553 : int i, n = gimple_phi_num_args (loop_phi_node);
1451 10849553 : tree evolution_function = chrec_not_analyzed_yet;
1452 10849553 : class loop *loop = loop_containing_stmt (loop_phi_node);
1453 10849553 : basic_block bb;
1454 10849553 : static bool simplify_peeled_chrec_p = true;
1455 :
1456 10849553 : if (dump_file && (dump_flags & TDF_SCEV))
1457 : {
1458 3 : fprintf (dump_file, "(analyze_evolution_in_loop \n");
1459 3 : fprintf (dump_file, " (loop_phi_node = ");
1460 3 : print_gimple_stmt (dump_file, loop_phi_node, 0);
1461 3 : fprintf (dump_file, ")\n");
1462 : }
1463 :
1464 28659980 : for (i = 0; i < n; i++)
1465 : {
1466 20411104 : tree arg = PHI_ARG_DEF (loop_phi_node, i);
1467 20411104 : tree ev_fn = chrec_dont_know;
1468 20411104 : t_bool res;
1469 :
1470 : /* Select the edges that enter the loop body. */
1471 20411104 : bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
1472 20411104 : if (!flow_bb_inside_loop_p (loop, bb))
1473 9561551 : continue;
1474 :
1475 10849553 : if (TREE_CODE (arg) == SSA_NAME)
1476 : {
1477 10737717 : bool val = false;
1478 :
1479 : /* Pass in the initial condition to the follow edge function. */
1480 10737717 : scev_dfs dfs (loop, loop_phi_node, init_cond);
1481 10737717 : res = dfs.get_ev (&ev_fn, arg);
1482 :
1483 : /* If ev_fn has no evolution in the inner loop, and the
1484 : init_cond is not equal to ev_fn, then we have an
1485 : ambiguity between two possible values, as we cannot know
1486 : the number of iterations at this point. */
1487 10737717 : if (TREE_CODE (ev_fn) != POLYNOMIAL_CHREC
1488 2473411 : && no_evolution_in_loop_p (ev_fn, loop->num, &val) && val
1489 10737723 : && !operand_equal_p (init_cond, ev_fn, 0))
1490 0 : ev_fn = chrec_dont_know;
1491 : }
1492 : else
1493 : res = t_false;
1494 :
1495 : /* When it is impossible to go back on the same
1496 : loop_phi_node by following the ssa edges, the
1497 : evolution is represented by a peeled chrec, i.e. the
1498 : first iteration, EV_FN has the value INIT_COND, then
1499 : all the other iterations it has the value of ARG.
1500 : For the moment, PEELED_CHREC nodes are not built. */
1501 10737717 : if (res != t_true)
1502 : {
1503 2290003 : ev_fn = chrec_dont_know;
1504 : /* Try to recognize POLYNOMIAL_CHREC which appears in
1505 : the form of PEELED_CHREC, but guard the process with
1506 : a bool variable to keep the analyzer from infinite
1507 : recurrence for real PEELED_RECs. */
1508 2290003 : if (simplify_peeled_chrec_p && TREE_CODE (arg) == SSA_NAME)
1509 : {
1510 1570935 : simplify_peeled_chrec_p = false;
1511 1570935 : ev_fn = simplify_peeled_chrec (loop, arg, init_cond);
1512 1570935 : simplify_peeled_chrec_p = true;
1513 : }
1514 : }
1515 :
1516 : /* When there are multiple back edges of the loop (which in fact never
1517 : happens currently, but nevertheless), merge their evolutions. */
1518 10849553 : evolution_function = chrec_merge (evolution_function, ev_fn);
1519 :
1520 10849553 : if (evolution_function == chrec_dont_know)
1521 : break;
1522 : }
1523 :
1524 10849553 : if (dump_file && (dump_flags & TDF_SCEV))
1525 : {
1526 3 : fprintf (dump_file, " (evolution_function = ");
1527 3 : print_generic_expr (dump_file, evolution_function);
1528 3 : fprintf (dump_file, "))\n");
1529 : }
1530 :
1531 10849553 : return evolution_function;
1532 : }
1533 :
1534 : /* Looks to see if VAR is a copy of a constant (via straightforward assignments
1535 : or degenerate phi's). If so, returns the constant; else, returns VAR. */
1536 :
1537 : static tree
1538 22449906 : follow_copies_to_constant (tree var)
1539 : {
1540 22449906 : tree res = var;
1541 22449906 : while (TREE_CODE (res) == SSA_NAME
1542 : /* We face not updated SSA form in multiple places and this walk
1543 : may end up in sibling loops so we have to guard it. */
1544 27159258 : && !name_registered_for_update_p (res))
1545 : {
1546 16023178 : gimple *def = SSA_NAME_DEF_STMT (res);
1547 16023178 : if (gphi *phi = dyn_cast <gphi *> (def))
1548 : {
1549 4149443 : if (tree rhs = degenerate_phi_result (phi))
1550 : res = rhs;
1551 : else
1552 : break;
1553 : }
1554 11873735 : else if (gimple_assign_single_p (def))
1555 : /* Will exit loop if not an SSA_NAME. */
1556 4383647 : res = gimple_assign_rhs1 (def);
1557 : else
1558 : break;
1559 : }
1560 22449906 : if (CONSTANT_CLASS_P (res))
1561 6602811 : return res;
1562 : return var;
1563 : }
1564 :
1565 : /* Given a loop-phi-node, return the initial conditions of the
1566 : variable on entry of the loop. When the CCP has propagated
1567 : constants into the loop-phi-node, the initial condition is
1568 : instantiated, otherwise the initial condition is kept symbolic.
1569 : This analyzer does not analyze the evolution outside the current
1570 : loop, and leaves this task to the on-demand tree reconstructor. */
1571 :
1572 : static tree
1573 10849553 : analyze_initial_condition (gphi *loop_phi_node)
1574 : {
1575 10849553 : int i, n;
1576 10849553 : tree init_cond = chrec_not_analyzed_yet;
1577 10849553 : class loop *loop = loop_containing_stmt (loop_phi_node);
1578 :
1579 10849553 : if (dump_file && (dump_flags & TDF_SCEV))
1580 : {
1581 3 : fprintf (dump_file, "(analyze_initial_condition \n");
1582 3 : fprintf (dump_file, " (loop_phi_node = \n");
1583 3 : print_gimple_stmt (dump_file, loop_phi_node, 0);
1584 3 : fprintf (dump_file, ")\n");
1585 : }
1586 :
1587 10849553 : n = gimple_phi_num_args (loop_phi_node);
1588 32548659 : for (i = 0; i < n; i++)
1589 : {
1590 21699106 : tree branch = PHI_ARG_DEF (loop_phi_node, i);
1591 21699106 : basic_block bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
1592 :
1593 : /* When the branch is oriented to the loop's body, it does
1594 : not contribute to the initial condition. */
1595 21699106 : if (flow_bb_inside_loop_p (loop, bb))
1596 10849553 : continue;
1597 :
1598 10849553 : if (init_cond == chrec_not_analyzed_yet)
1599 : {
1600 10849553 : init_cond = branch;
1601 10849553 : continue;
1602 : }
1603 :
1604 0 : if (TREE_CODE (branch) == SSA_NAME)
1605 : {
1606 0 : init_cond = chrec_dont_know;
1607 0 : break;
1608 : }
1609 :
1610 0 : init_cond = chrec_merge (init_cond, branch);
1611 : }
1612 :
1613 : /* Ooops -- a loop without an entry??? */
1614 10849553 : if (init_cond == chrec_not_analyzed_yet)
1615 0 : init_cond = chrec_dont_know;
1616 :
1617 : /* We may not have fully constant propagated IL. Handle degenerate PHIs here
1618 : to not miss important early loop unrollings. */
1619 10849553 : init_cond = follow_copies_to_constant (init_cond);
1620 :
1621 10849553 : if (dump_file && (dump_flags & TDF_SCEV))
1622 : {
1623 3 : fprintf (dump_file, " (init_cond = ");
1624 3 : print_generic_expr (dump_file, init_cond);
1625 3 : fprintf (dump_file, "))\n");
1626 : }
1627 :
1628 10849553 : return init_cond;
1629 : }
1630 :
1631 : /* Analyze the scalar evolution for LOOP_PHI_NODE. */
1632 :
1633 : static tree
1634 10849553 : interpret_loop_phi (class loop *loop, gphi *loop_phi_node)
1635 : {
1636 10849553 : class loop *phi_loop = loop_containing_stmt (loop_phi_node);
1637 10849553 : tree init_cond;
1638 :
1639 10849553 : gcc_assert (phi_loop == loop);
1640 :
1641 : /* Otherwise really interpret the loop phi. */
1642 10849553 : init_cond = analyze_initial_condition (loop_phi_node);
1643 10849553 : return analyze_evolution_in_loop (loop_phi_node, init_cond);
1644 : }
1645 :
1646 : /* This function merges the branches of a condition-phi-node,
1647 : contained in the outermost loop, and whose arguments are already
1648 : analyzed. */
1649 :
1650 : static tree
1651 2613268 : interpret_condition_phi (class loop *loop, gphi *condition_phi)
1652 : {
1653 2613268 : int i, n = gimple_phi_num_args (condition_phi);
1654 2613268 : tree res = chrec_not_analyzed_yet;
1655 :
1656 5493065 : for (i = 0; i < n; i++)
1657 : {
1658 4956083 : tree branch_chrec;
1659 :
1660 4956083 : if (backedge_phi_arg_p (condition_phi, i))
1661 : {
1662 41612 : res = chrec_dont_know;
1663 41612 : break;
1664 : }
1665 :
1666 4914471 : branch_chrec = analyze_scalar_evolution
1667 4914471 : (loop, PHI_ARG_DEF (condition_phi, i));
1668 :
1669 4914471 : res = chrec_merge (res, branch_chrec);
1670 4914471 : if (res == chrec_dont_know)
1671 : break;
1672 : }
1673 :
1674 2613268 : return res;
1675 : }
1676 :
1677 : /* Interpret the operation RHS1 OP RHS2. If we didn't
1678 : analyze this node before, follow the definitions until ending
1679 : either on an analyzed GIMPLE_ASSIGN, or on a loop-phi-node. On the
1680 : return path, this function propagates evolutions (ala constant copy
1681 : propagation). OPND1 is not a GIMPLE expression because we could
1682 : analyze the effect of an inner loop: see interpret_loop_phi. */
1683 :
1684 : static tree
1685 44631861 : interpret_rhs_expr (class loop *loop, gimple *at_stmt,
1686 : tree type, tree rhs1, enum tree_code code, tree rhs2)
1687 : {
1688 44631861 : tree res, chrec1, chrec2, ctype;
1689 44631861 : gimple *def;
1690 :
1691 44631861 : if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
1692 : {
1693 10790711 : if (is_gimple_min_invariant (rhs1))
1694 2454765 : return chrec_convert (type, rhs1, at_stmt);
1695 :
1696 8335946 : if (code == SSA_NAME)
1697 131539 : return chrec_convert (type, analyze_scalar_evolution (loop, rhs1),
1698 131539 : at_stmt);
1699 : }
1700 :
1701 42045557 : switch (code)
1702 : {
1703 338192 : case ADDR_EXPR:
1704 338192 : if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF
1705 338192 : || handled_component_p (TREE_OPERAND (rhs1, 0)))
1706 : {
1707 337935 : machine_mode mode;
1708 337935 : poly_int64 bitsize, bitpos;
1709 337935 : int unsignedp, reversep;
1710 337935 : int volatilep = 0;
1711 337935 : tree base, offset;
1712 337935 : tree chrec3;
1713 337935 : tree unitpos;
1714 :
1715 337935 : base = get_inner_reference (TREE_OPERAND (rhs1, 0),
1716 : &bitsize, &bitpos, &offset, &mode,
1717 : &unsignedp, &reversep, &volatilep);
1718 :
1719 337935 : if (TREE_CODE (base) == MEM_REF)
1720 : {
1721 258717 : rhs2 = TREE_OPERAND (base, 1);
1722 258717 : rhs1 = TREE_OPERAND (base, 0);
1723 :
1724 258717 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1725 258717 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1726 258717 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1727 258717 : chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt);
1728 258717 : chrec1 = instantiate_parameters (loop, chrec1);
1729 258717 : chrec2 = instantiate_parameters (loop, chrec2);
1730 258717 : res = chrec_fold_plus (type, chrec1, chrec2);
1731 : }
1732 : else
1733 : {
1734 79218 : chrec1 = analyze_scalar_evolution_for_address_of (loop, base);
1735 79218 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1736 79218 : res = chrec1;
1737 : }
1738 :
1739 337935 : if (offset != NULL_TREE)
1740 : {
1741 150086 : chrec2 = analyze_scalar_evolution (loop, offset);
1742 150086 : chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt);
1743 150086 : chrec2 = instantiate_parameters (loop, chrec2);
1744 150086 : res = chrec_fold_plus (type, res, chrec2);
1745 : }
1746 :
1747 337935 : if (maybe_ne (bitpos, 0))
1748 : {
1749 124561 : unitpos = size_int (exact_div (bitpos, BITS_PER_UNIT));
1750 124561 : chrec3 = analyze_scalar_evolution (loop, unitpos);
1751 124561 : chrec3 = chrec_convert (TREE_TYPE (unitpos), chrec3, at_stmt);
1752 124561 : chrec3 = instantiate_parameters (loop, chrec3);
1753 124561 : res = chrec_fold_plus (type, res, chrec3);
1754 : }
1755 : }
1756 : else
1757 257 : res = chrec_dont_know;
1758 : break;
1759 :
1760 3474222 : case POINTER_PLUS_EXPR:
1761 3474222 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1762 3474222 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1763 3474222 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1764 3474222 : chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt);
1765 3474222 : chrec1 = instantiate_parameters (loop, chrec1);
1766 3474222 : chrec2 = instantiate_parameters (loop, chrec2);
1767 3474222 : res = chrec_fold_plus (type, chrec1, chrec2);
1768 3474222 : break;
1769 :
1770 117733 : case POINTER_DIFF_EXPR:
1771 117733 : {
1772 117733 : tree utype = unsigned_type_for (type);
1773 117733 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1774 117733 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1775 117733 : chrec1 = chrec_convert (utype, chrec1, at_stmt);
1776 117733 : chrec2 = chrec_convert (utype, chrec2, at_stmt);
1777 117733 : chrec1 = instantiate_parameters (loop, chrec1);
1778 117733 : chrec2 = instantiate_parameters (loop, chrec2);
1779 117733 : res = chrec_fold_minus (utype, chrec1, chrec2);
1780 117733 : res = chrec_convert (type, res, at_stmt);
1781 117733 : break;
1782 : }
1783 :
1784 11775874 : case PLUS_EXPR:
1785 11775874 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1786 11775874 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1787 11775874 : ctype = type;
1788 : /* When the stmt is conditionally executed re-write the CHREC
1789 : into a form that has well-defined behavior on overflow. */
1790 11775874 : if (at_stmt
1791 10655599 : && INTEGRAL_TYPE_P (type)
1792 10561224 : && ! TYPE_OVERFLOW_WRAPS (type)
1793 19836024 : && ! dominated_by_p (CDI_DOMINATORS, loop->latch,
1794 8060150 : gimple_bb (at_stmt)))
1795 707121 : ctype = unsigned_type_for (type);
1796 11775874 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1797 11775874 : chrec2 = chrec_convert (ctype, chrec2, at_stmt);
1798 11775874 : chrec1 = instantiate_parameters (loop, chrec1);
1799 11775874 : chrec2 = instantiate_parameters (loop, chrec2);
1800 11775874 : res = chrec_fold_plus (ctype, chrec1, chrec2);
1801 11775874 : if (type != ctype)
1802 707121 : res = chrec_convert (type, res, at_stmt);
1803 : break;
1804 :
1805 1462646 : case MINUS_EXPR:
1806 1462646 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1807 1462646 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1808 1462646 : ctype = type;
1809 : /* When the stmt is conditionally executed re-write the CHREC
1810 : into a form that has well-defined behavior on overflow. */
1811 1462646 : if (at_stmt
1812 1398781 : && INTEGRAL_TYPE_P (type)
1813 1362126 : && ! TYPE_OVERFLOW_WRAPS (type)
1814 1996177 : && ! dominated_by_p (CDI_DOMINATORS,
1815 533531 : loop->latch, gimple_bb (at_stmt)))
1816 135591 : ctype = unsigned_type_for (type);
1817 1462646 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1818 1462646 : chrec2 = chrec_convert (ctype, chrec2, at_stmt);
1819 1462646 : chrec1 = instantiate_parameters (loop, chrec1);
1820 1462646 : chrec2 = instantiate_parameters (loop, chrec2);
1821 1462646 : res = chrec_fold_minus (ctype, chrec1, chrec2);
1822 1462646 : if (type != ctype)
1823 135591 : res = chrec_convert (type, res, at_stmt);
1824 : break;
1825 :
1826 82913 : case NEGATE_EXPR:
1827 82913 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1828 82913 : ctype = type;
1829 : /* When the stmt is conditionally executed re-write the CHREC
1830 : into a form that has well-defined behavior on overflow. */
1831 82913 : if (at_stmt
1832 71506 : && INTEGRAL_TYPE_P (type)
1833 69726 : && ! TYPE_OVERFLOW_WRAPS (type)
1834 121078 : && ! dominated_by_p (CDI_DOMINATORS,
1835 38165 : loop->latch, gimple_bb (at_stmt)))
1836 7229 : ctype = unsigned_type_for (type);
1837 82913 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1838 : /* TYPE may be integer, real or complex, so use fold_convert. */
1839 82913 : chrec1 = instantiate_parameters (loop, chrec1);
1840 82913 : res = chrec_fold_multiply (ctype, chrec1,
1841 : fold_convert (ctype, integer_minus_one_node));
1842 82913 : if (type != ctype)
1843 7229 : res = chrec_convert (type, res, at_stmt);
1844 : break;
1845 :
1846 35960 : case BIT_NOT_EXPR:
1847 : /* Handle ~X as -1 - X. */
1848 35960 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1849 35960 : chrec1 = chrec_convert (type, chrec1, at_stmt);
1850 35960 : chrec1 = instantiate_parameters (loop, chrec1);
1851 35960 : res = chrec_fold_minus (type,
1852 : fold_convert (type, integer_minus_one_node),
1853 : chrec1);
1854 35960 : break;
1855 :
1856 6062245 : case MULT_EXPR:
1857 6062245 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1858 6062245 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1859 6062245 : ctype = type;
1860 : /* When the stmt is conditionally executed re-write the CHREC
1861 : into a form that has well-defined behavior on overflow. */
1862 6062245 : if (at_stmt
1863 4151434 : && INTEGRAL_TYPE_P (type)
1864 4040777 : && ! TYPE_OVERFLOW_WRAPS (type)
1865 7882153 : && ! dominated_by_p (CDI_DOMINATORS,
1866 1819908 : loop->latch, gimple_bb (at_stmt)))
1867 161830 : ctype = unsigned_type_for (type);
1868 6062245 : chrec1 = chrec_convert (ctype, chrec1, at_stmt);
1869 6062245 : chrec2 = chrec_convert (ctype, chrec2, at_stmt);
1870 6062245 : chrec1 = instantiate_parameters (loop, chrec1);
1871 6062245 : chrec2 = instantiate_parameters (loop, chrec2);
1872 6062245 : res = chrec_fold_multiply (ctype, chrec1, chrec2);
1873 6062245 : if (type != ctype)
1874 161830 : res = chrec_convert (type, res, at_stmt);
1875 : break;
1876 :
1877 155244 : case LSHIFT_EXPR:
1878 155244 : {
1879 : /* Handle A<<B as A * (1<<B). */
1880 155244 : tree uns = unsigned_type_for (type);
1881 155244 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1882 155244 : chrec2 = analyze_scalar_evolution (loop, rhs2);
1883 155244 : chrec1 = chrec_convert (uns, chrec1, at_stmt);
1884 155244 : chrec1 = instantiate_parameters (loop, chrec1);
1885 155244 : chrec2 = instantiate_parameters (loop, chrec2);
1886 :
1887 155244 : tree one = build_int_cst (uns, 1);
1888 155244 : chrec2 = fold_build2 (LSHIFT_EXPR, uns, one, chrec2);
1889 155244 : res = chrec_fold_multiply (uns, chrec1, chrec2);
1890 155244 : res = chrec_convert (type, res, at_stmt);
1891 : }
1892 155244 : break;
1893 :
1894 8459230 : CASE_CONVERT:
1895 : /* In case we have a truncation of a widened operation that in
1896 : the truncated type has undefined overflow behavior analyze
1897 : the operation done in an unsigned type of the same precision
1898 : as the final truncation. We cannot derive a scalar evolution
1899 : for the widened operation but for the truncated result. */
1900 8459230 : if (TREE_CODE (type) == INTEGER_TYPE
1901 8167076 : && TREE_CODE (TREE_TYPE (rhs1)) == INTEGER_TYPE
1902 7639813 : && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (rhs1))
1903 464519 : && TYPE_OVERFLOW_UNDEFINED (type)
1904 269766 : && TREE_CODE (rhs1) == SSA_NAME
1905 269598 : && (def = SSA_NAME_DEF_STMT (rhs1))
1906 269598 : && is_gimple_assign (def)
1907 174917 : && TREE_CODE_CLASS (gimple_assign_rhs_code (def)) == tcc_binary
1908 8581825 : && TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST)
1909 : {
1910 88698 : tree utype = unsigned_type_for (type);
1911 88698 : chrec1 = interpret_rhs_expr (loop, at_stmt, utype,
1912 : gimple_assign_rhs1 (def),
1913 : gimple_assign_rhs_code (def),
1914 : gimple_assign_rhs2 (def));
1915 : }
1916 : else
1917 8370532 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1918 8459230 : res = chrec_convert (type, chrec1, at_stmt, true, rhs1);
1919 8459230 : break;
1920 :
1921 395575 : case BIT_AND_EXPR:
1922 : /* Given int variable A, handle A&0xffff as (int)(unsigned short)A.
1923 : If A is SCEV and its value is in the range of representable set
1924 : of type unsigned short, the result expression is a (no-overflow)
1925 : SCEV. */
1926 395575 : res = chrec_dont_know;
1927 395575 : if (tree_fits_uhwi_p (rhs2))
1928 : {
1929 270437 : int precision;
1930 270437 : unsigned HOST_WIDE_INT val = tree_to_uhwi (rhs2);
1931 :
1932 270437 : val ++;
1933 : /* Skip if value of rhs2 wraps in unsigned HOST_WIDE_INT or
1934 : it's not the maximum value of a smaller type than rhs1. */
1935 270437 : if (val != 0
1936 214209 : && (precision = exact_log2 (val)) > 0
1937 484646 : && (unsigned) precision < TYPE_PRECISION (TREE_TYPE (rhs1)))
1938 : {
1939 214209 : tree utype = build_nonstandard_integer_type (precision, 1);
1940 :
1941 214209 : if (TYPE_PRECISION (utype) < TYPE_PRECISION (TREE_TYPE (rhs1)))
1942 : {
1943 214209 : chrec1 = analyze_scalar_evolution (loop, rhs1);
1944 214209 : chrec1 = chrec_convert (utype, chrec1, at_stmt);
1945 214209 : res = chrec_convert (TREE_TYPE (rhs1), chrec1, at_stmt);
1946 : }
1947 : }
1948 : }
1949 : break;
1950 :
1951 9685723 : default:
1952 9685723 : res = chrec_dont_know;
1953 9685723 : break;
1954 : }
1955 :
1956 : return res;
1957 : }
1958 :
1959 : /* Interpret the expression EXPR. */
1960 :
1961 : static tree
1962 8845538 : interpret_expr (class loop *loop, gimple *at_stmt, tree expr)
1963 : {
1964 8845538 : enum tree_code code;
1965 8845538 : tree type = TREE_TYPE (expr), op0, op1;
1966 :
1967 8845538 : if (automatically_generated_chrec_p (expr))
1968 : return expr;
1969 :
1970 8840719 : if (TREE_CODE (expr) == POLYNOMIAL_CHREC
1971 8840231 : || TREE_CODE (expr) == CALL_EXPR
1972 17680882 : || get_gimple_rhs_class (TREE_CODE (expr)) == GIMPLE_TERNARY_RHS)
1973 : return chrec_dont_know;
1974 :
1975 8770286 : extract_ops_from_tree (expr, &code, &op0, &op1);
1976 :
1977 8770286 : return interpret_rhs_expr (loop, at_stmt, type,
1978 8770286 : op0, code, op1);
1979 : }
1980 :
1981 : /* Interpret the rhs of the assignment STMT. */
1982 :
1983 : static tree
1984 35772877 : interpret_gimple_assign (class loop *loop, gimple *stmt)
1985 : {
1986 35772877 : tree type = TREE_TYPE (gimple_assign_lhs (stmt));
1987 35772877 : enum tree_code code = gimple_assign_rhs_code (stmt);
1988 :
1989 35772877 : return interpret_rhs_expr (loop, stmt, type,
1990 : gimple_assign_rhs1 (stmt), code,
1991 35772877 : gimple_assign_rhs2 (stmt));
1992 : }
1993 :
1994 :
1995 :
1996 : /* This section contains all the entry points:
1997 : - number_of_iterations_in_loop,
1998 : - analyze_scalar_evolution,
1999 : - instantiate_parameters.
2000 : */
2001 :
2002 : /* Helper recursive function. */
2003 :
2004 : static tree
2005 74171899 : analyze_scalar_evolution_1 (class loop *loop, tree var)
2006 : {
2007 74171899 : gimple *def;
2008 74171899 : basic_block bb;
2009 74171899 : class loop *def_loop;
2010 74171899 : tree res;
2011 :
2012 74171899 : if (TREE_CODE (var) != SSA_NAME)
2013 8845538 : return interpret_expr (loop, NULL, var);
2014 :
2015 65326361 : def = SSA_NAME_DEF_STMT (var);
2016 65326361 : bb = gimple_bb (def);
2017 65326361 : def_loop = bb->loop_father;
2018 :
2019 65326361 : if (!flow_bb_inside_loop_p (loop, bb))
2020 : {
2021 : /* Keep symbolic form, but look through obvious copies for constants. */
2022 11600353 : res = follow_copies_to_constant (var);
2023 11600353 : goto set_and_end;
2024 : }
2025 :
2026 53726008 : if (loop != def_loop)
2027 : {
2028 3924899 : res = analyze_scalar_evolution_1 (def_loop, var);
2029 3924899 : class loop *loop_to_skip = superloop_at_depth (def_loop,
2030 3924899 : loop_depth (loop) + 1);
2031 3924899 : res = compute_overall_effect_of_inner_loop (loop_to_skip, res);
2032 3924899 : if (chrec_contains_symbols_defined_in_loop (res, loop->num))
2033 294611 : res = analyze_scalar_evolution_1 (loop, res);
2034 3924899 : goto set_and_end;
2035 : }
2036 :
2037 49801109 : switch (gimple_code (def))
2038 : {
2039 35772877 : case GIMPLE_ASSIGN:
2040 35772877 : res = interpret_gimple_assign (loop, def);
2041 35772877 : break;
2042 :
2043 13462821 : case GIMPLE_PHI:
2044 26925642 : if (loop_phi_node_p (def))
2045 10849553 : res = interpret_loop_phi (loop, as_a <gphi *> (def));
2046 : else
2047 2613268 : res = interpret_condition_phi (loop, as_a <gphi *> (def));
2048 : break;
2049 :
2050 565411 : default:
2051 565411 : res = chrec_dont_know;
2052 565411 : break;
2053 : }
2054 :
2055 65326361 : set_and_end:
2056 :
2057 : /* Keep the symbolic form. */
2058 65326361 : if (res == chrec_dont_know)
2059 23939963 : res = var;
2060 :
2061 65326361 : if (loop == def_loop)
2062 49801109 : set_scalar_evolution (block_before_loop (loop), var, res);
2063 :
2064 : return res;
2065 : }
2066 :
2067 : /* Analyzes and returns the scalar evolution of the ssa_name VAR in
2068 : LOOP. LOOP is the loop in which the variable is used.
2069 :
2070 : Example of use: having a pointer VAR to a SSA_NAME node, STMT a
2071 : pointer to the statement that uses this variable, in order to
2072 : determine the evolution function of the variable, use the following
2073 : calls:
2074 :
2075 : loop_p loop = loop_containing_stmt (stmt);
2076 : tree chrec_with_symbols = analyze_scalar_evolution (loop, var);
2077 : tree chrec_instantiated = instantiate_parameters (loop, chrec_with_symbols);
2078 : */
2079 :
2080 : tree
2081 193892793 : analyze_scalar_evolution (class loop *loop, tree var)
2082 : {
2083 193892793 : tree res;
2084 :
2085 : /* ??? Fix callers. */
2086 193892793 : if (! loop)
2087 : return var;
2088 :
2089 193733911 : if (dump_file && (dump_flags & TDF_SCEV))
2090 : {
2091 36 : fprintf (dump_file, "(analyze_scalar_evolution \n");
2092 36 : fprintf (dump_file, " (loop_nb = %d)\n", loop->num);
2093 36 : fprintf (dump_file, " (scalar = ");
2094 36 : print_generic_expr (dump_file, var);
2095 36 : fprintf (dump_file, ")\n");
2096 : }
2097 :
2098 193733911 : res = get_scalar_evolution (block_before_loop (loop), var);
2099 193733911 : if (res == chrec_not_analyzed_yet)
2100 : {
2101 : /* We'll recurse into instantiate_scev, avoid tearing down the
2102 : instantiate cache repeatedly and keep it live from here. */
2103 69952389 : bool destr = false;
2104 69952389 : if (!global_cache)
2105 : {
2106 41890729 : global_cache = new instantiate_cache_type;
2107 41890729 : destr = true;
2108 : }
2109 69952389 : res = analyze_scalar_evolution_1 (loop, var);
2110 69952389 : if (destr)
2111 : {
2112 41890729 : delete global_cache;
2113 41890729 : global_cache = NULL;
2114 : }
2115 : }
2116 :
2117 193733911 : if (dump_file && (dump_flags & TDF_SCEV))
2118 36 : fprintf (dump_file, ")\n");
2119 :
2120 : return res;
2121 : }
2122 :
2123 : /* If CHREC doesn't overflow, set the nonwrapping flag. */
2124 :
2125 10646951 : void record_nonwrapping_chrec (tree chrec)
2126 : {
2127 10646951 : CHREC_NOWRAP(chrec) = 1;
2128 :
2129 10646951 : if (dump_file && (dump_flags & TDF_SCEV))
2130 : {
2131 6 : fprintf (dump_file, "(record_nonwrapping_chrec: ");
2132 6 : print_generic_expr (dump_file, chrec);
2133 6 : fprintf (dump_file, ")\n");
2134 : }
2135 10646951 : }
2136 :
2137 : /* Return true if CHREC's nonwrapping flag is set. */
2138 :
2139 226296 : bool nonwrapping_chrec_p (tree chrec)
2140 : {
2141 226296 : if (!chrec || TREE_CODE(chrec) != POLYNOMIAL_CHREC)
2142 : return false;
2143 :
2144 226296 : return CHREC_NOWRAP(chrec);
2145 : }
2146 :
2147 : /* Analyzes and returns the scalar evolution of VAR address in LOOP. */
2148 :
2149 : static tree
2150 79218 : analyze_scalar_evolution_for_address_of (class loop *loop, tree var)
2151 : {
2152 79218 : return analyze_scalar_evolution (loop, build_fold_addr_expr (var));
2153 : }
2154 :
2155 : /* Analyze scalar evolution of use of VERSION in USE_LOOP with respect to
2156 : WRTO_LOOP (which should be a superloop of USE_LOOP)
2157 :
2158 : FOLDED_CASTS is set to true if resolve_mixers used
2159 : chrec_convert_aggressive (TODO -- not really, we are way too conservative
2160 : at the moment in order to keep things simple).
2161 :
2162 : To illustrate the meaning of USE_LOOP and WRTO_LOOP, consider the following
2163 : example:
2164 :
2165 : for (i = 0; i < 100; i++) -- loop 1
2166 : {
2167 : for (j = 0; j < 100; j++) -- loop 2
2168 : {
2169 : k1 = i;
2170 : k2 = j;
2171 :
2172 : use2 (k1, k2);
2173 :
2174 : for (t = 0; t < 100; t++) -- loop 3
2175 : use3 (k1, k2);
2176 :
2177 : }
2178 : use1 (k1, k2);
2179 : }
2180 :
2181 : Both k1 and k2 are invariants in loop3, thus
2182 : analyze_scalar_evolution_in_loop (loop3, loop3, k1) = k1
2183 : analyze_scalar_evolution_in_loop (loop3, loop3, k2) = k2
2184 :
2185 : As they are invariant, it does not matter whether we consider their
2186 : usage in loop 3 or loop 2, hence
2187 : analyze_scalar_evolution_in_loop (loop2, loop3, k1) =
2188 : analyze_scalar_evolution_in_loop (loop2, loop2, k1) = i
2189 : analyze_scalar_evolution_in_loop (loop2, loop3, k2) =
2190 : analyze_scalar_evolution_in_loop (loop2, loop2, k2) = [0,+,1]_2
2191 :
2192 : Similarly for their evolutions with respect to loop 1. The values of K2
2193 : in the use in loop 2 vary independently on loop 1, thus we cannot express
2194 : the evolution with respect to loop 1:
2195 : analyze_scalar_evolution_in_loop (loop1, loop3, k1) =
2196 : analyze_scalar_evolution_in_loop (loop1, loop2, k1) = [0,+,1]_1
2197 : analyze_scalar_evolution_in_loop (loop1, loop3, k2) =
2198 : analyze_scalar_evolution_in_loop (loop1, loop2, k2) = dont_know
2199 :
2200 : The value of k2 in the use in loop 1 is known, though:
2201 : analyze_scalar_evolution_in_loop (loop1, loop1, k1) = [0,+,1]_1
2202 : analyze_scalar_evolution_in_loop (loop1, loop1, k2) = 100
2203 : */
2204 :
2205 : static tree
2206 49437485 : analyze_scalar_evolution_in_loop (class loop *wrto_loop, class loop *use_loop,
2207 : tree version, bool *folded_casts)
2208 : {
2209 49437485 : bool val = false;
2210 49437485 : tree ev = version, tmp;
2211 :
2212 : /* We cannot just do
2213 :
2214 : tmp = analyze_scalar_evolution (use_loop, version);
2215 : ev = resolve_mixers (wrto_loop, tmp, folded_casts);
2216 :
2217 : as resolve_mixers would query the scalar evolution with respect to
2218 : wrto_loop. For example, in the situation described in the function
2219 : comment, suppose that wrto_loop = loop1, use_loop = loop3 and
2220 : version = k2. Then
2221 :
2222 : analyze_scalar_evolution (use_loop, version) = k2
2223 :
2224 : and resolve_mixers (loop1, k2, folded_casts) finds that the value of
2225 : k2 in loop 1 is 100, which is a wrong result, since we are interested
2226 : in the value in loop 3.
2227 :
2228 : Instead, we need to proceed from use_loop to wrto_loop loop by loop,
2229 : each time checking that there is no evolution in the inner loop. */
2230 :
2231 49437485 : if (folded_casts)
2232 49437485 : *folded_casts = false;
2233 51739659 : while (1)
2234 : {
2235 50588572 : tmp = analyze_scalar_evolution (use_loop, ev);
2236 50588572 : ev = resolve_mixers (use_loop, tmp, folded_casts);
2237 :
2238 50588572 : if (use_loop == wrto_loop)
2239 : return ev;
2240 :
2241 : /* If the value of the use changes in the inner loop, we cannot express
2242 : its value in the outer loop (we might try to return interval chrec,
2243 : but we do not have a user for it anyway) */
2244 4295923 : if (!no_evolution_in_loop_p (ev, use_loop->num, &val)
2245 4295923 : || !val)
2246 3144836 : return chrec_dont_know;
2247 :
2248 1151087 : use_loop = loop_outer (use_loop);
2249 : }
2250 : }
2251 :
2252 :
2253 : /* Computes a hash function for database element ELT. */
2254 :
2255 : static inline hashval_t
2256 269261 : hash_idx_scev_info (const void *elt_)
2257 : {
2258 269261 : unsigned idx = ((size_t) elt_) - 2;
2259 269261 : return scev_info_hasher::hash (&global_cache->entries[idx]);
2260 : }
2261 :
2262 : /* Compares database elements E1 and E2. */
2263 :
2264 : static inline int
2265 31670120 : eq_idx_scev_info (const void *e1, const void *e2)
2266 : {
2267 31670120 : unsigned idx1 = ((size_t) e1) - 2;
2268 31670120 : return scev_info_hasher::equal (&global_cache->entries[idx1],
2269 31670120 : (const scev_info_str *) e2);
2270 : }
2271 :
2272 : /* Returns from CACHE the slot number of the cached chrec for NAME. */
2273 :
2274 : static unsigned
2275 63289008 : get_instantiated_value_entry (instantiate_cache_type &cache,
2276 : tree name, edge instantiate_below)
2277 : {
2278 63289008 : if (!cache.map)
2279 : {
2280 29076953 : cache.map = htab_create (10, hash_idx_scev_info, eq_idx_scev_info, NULL);
2281 29076953 : cache.entries.create (10);
2282 : }
2283 :
2284 63289008 : scev_info_str e;
2285 63289008 : e.name_version = SSA_NAME_VERSION (name);
2286 63289008 : e.instantiated_below = instantiate_below->dest->index;
2287 63289008 : void **slot = htab_find_slot_with_hash (cache.map, &e,
2288 : scev_info_hasher::hash (&e), INSERT);
2289 63289008 : if (!*slot)
2290 : {
2291 32730306 : e.chrec = chrec_not_analyzed_yet;
2292 32730306 : *slot = (void *)(size_t)(cache.entries.length () + 2);
2293 32730306 : cache.entries.safe_push (e);
2294 : }
2295 :
2296 63289008 : return ((size_t)*slot) - 2;
2297 : }
2298 :
2299 :
2300 : /* Return the closed_loop_phi node for VAR. If there is none, return
2301 : NULL_TREE. */
2302 :
2303 : static tree
2304 1879943 : loop_closed_phi_def (tree var)
2305 : {
2306 1879943 : class loop *loop;
2307 1879943 : edge exit;
2308 1879943 : gphi *phi;
2309 1879943 : gphi_iterator psi;
2310 :
2311 1879943 : if (var == NULL_TREE
2312 1879943 : || TREE_CODE (var) != SSA_NAME)
2313 : return NULL_TREE;
2314 :
2315 1879943 : loop = loop_containing_stmt (SSA_NAME_DEF_STMT (var));
2316 1879943 : exit = single_exit (loop);
2317 1879943 : if (!exit)
2318 : return NULL_TREE;
2319 :
2320 1574094 : for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi))
2321 : {
2322 964159 : phi = psi.phi ();
2323 964159 : if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var)
2324 261278 : return PHI_RESULT (phi);
2325 : }
2326 :
2327 : return NULL_TREE;
2328 : }
2329 :
2330 : static tree instantiate_scev_r (edge, class loop *, class loop *,
2331 : tree, bool *, int);
2332 :
2333 : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2334 : and EVOLUTION_LOOP, that were left under a symbolic form.
2335 :
2336 : CHREC is an SSA_NAME to be instantiated.
2337 :
2338 : CACHE is the cache of already instantiated values.
2339 :
2340 : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2341 : conversions that may wrap in signed/pointer type are folded, as long
2342 : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2343 : then we don't do such fold.
2344 :
2345 : SIZE_EXPR is used for computing the size of the expression to be
2346 : instantiated, and to stop if it exceeds some limit. */
2347 :
2348 : static tree
2349 110799703 : instantiate_scev_name (edge instantiate_below,
2350 : class loop *evolution_loop, class loop *inner_loop,
2351 : tree chrec,
2352 : bool *fold_conversions,
2353 : int size_expr)
2354 : {
2355 110799703 : tree res;
2356 110799703 : class loop *def_loop;
2357 110799703 : basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (chrec));
2358 :
2359 : /* A parameter, nothing to do. */
2360 110799703 : if (!def_bb
2361 110799703 : || !dominated_by_p (CDI_DOMINATORS, def_bb, instantiate_below->dest))
2362 47510695 : return chrec;
2363 :
2364 : /* We cache the value of instantiated variable to avoid exponential
2365 : time complexity due to reevaluations. We also store the convenient
2366 : value in the cache in order to prevent infinite recursion -- we do
2367 : not want to instantiate the SSA_NAME if it is in a mixer
2368 : structure. This is used for avoiding the instantiation of
2369 : recursively defined functions, such as:
2370 :
2371 : | a_2 -> {0, +, 1, +, a_2}_1 */
2372 :
2373 63289008 : unsigned si = get_instantiated_value_entry (*global_cache,
2374 : chrec, instantiate_below);
2375 63289008 : if (global_cache->get (si) != chrec_not_analyzed_yet)
2376 : return global_cache->get (si);
2377 :
2378 : /* On recursion return chrec_dont_know. */
2379 32730306 : global_cache->set (si, chrec_dont_know);
2380 :
2381 32730306 : def_loop = find_common_loop (evolution_loop, def_bb->loop_father);
2382 :
2383 32730306 : if (! dominated_by_p (CDI_DOMINATORS,
2384 32730306 : def_loop->header, instantiate_below->dest))
2385 : {
2386 190855 : gimple *def = SSA_NAME_DEF_STMT (chrec);
2387 190855 : if (gassign *ass = dyn_cast <gassign *> (def))
2388 : {
2389 135129 : switch (gimple_assign_rhs_class (ass))
2390 : {
2391 5581 : case GIMPLE_UNARY_RHS:
2392 5581 : {
2393 5581 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2394 : inner_loop, gimple_assign_rhs1 (ass),
2395 : fold_conversions, size_expr);
2396 5581 : if (op0 == chrec_dont_know)
2397 : return chrec_dont_know;
2398 1392 : res = fold_build1 (gimple_assign_rhs_code (ass),
2399 : TREE_TYPE (chrec), op0);
2400 1392 : break;
2401 : }
2402 54133 : case GIMPLE_BINARY_RHS:
2403 54133 : {
2404 54133 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2405 : inner_loop, gimple_assign_rhs1 (ass),
2406 : fold_conversions, size_expr);
2407 54133 : if (op0 == chrec_dont_know)
2408 : return chrec_dont_know;
2409 12160 : tree op1 = instantiate_scev_r (instantiate_below, evolution_loop,
2410 : inner_loop, gimple_assign_rhs2 (ass),
2411 : fold_conversions, size_expr);
2412 6080 : if (op1 == chrec_dont_know)
2413 : return chrec_dont_know;
2414 2315 : res = fold_build2 (gimple_assign_rhs_code (ass),
2415 : TREE_TYPE (chrec), op0, op1);
2416 2315 : break;
2417 : }
2418 75415 : default:
2419 75415 : res = chrec_dont_know;
2420 : }
2421 : }
2422 : else
2423 55726 : res = chrec_dont_know;
2424 134848 : global_cache->set (si, res);
2425 134848 : return res;
2426 : }
2427 :
2428 : /* If the analysis yields a parametric chrec, instantiate the
2429 : result again. */
2430 32539451 : res = analyze_scalar_evolution (def_loop, chrec);
2431 :
2432 : /* Don't instantiate default definitions. */
2433 32539451 : if (TREE_CODE (res) == SSA_NAME
2434 32539451 : && SSA_NAME_IS_DEFAULT_DEF (res))
2435 : ;
2436 :
2437 : /* Don't instantiate loop-closed-ssa phi nodes. */
2438 32518631 : else if (TREE_CODE (res) == SSA_NAME
2439 95800496 : && loop_depth (loop_containing_stmt (SSA_NAME_DEF_STMT (res)))
2440 31641307 : > loop_depth (def_loop))
2441 : {
2442 1902594 : if (res == chrec)
2443 1879943 : res = loop_closed_phi_def (chrec);
2444 : else
2445 : res = chrec;
2446 :
2447 : /* When there is no loop_closed_phi_def, it means that the
2448 : variable is not used after the loop: try to still compute the
2449 : value of the variable when exiting the loop. */
2450 1902594 : if (res == NULL_TREE)
2451 : {
2452 1618665 : loop_p loop = loop_containing_stmt (SSA_NAME_DEF_STMT (chrec));
2453 1618665 : res = analyze_scalar_evolution (loop, chrec);
2454 1618665 : res = compute_overall_effect_of_inner_loop (loop, res);
2455 1618665 : res = instantiate_scev_r (instantiate_below, evolution_loop,
2456 : inner_loop, res,
2457 : fold_conversions, size_expr);
2458 : }
2459 283929 : else if (dominated_by_p (CDI_DOMINATORS,
2460 283929 : gimple_bb (SSA_NAME_DEF_STMT (res)),
2461 283929 : instantiate_below->dest))
2462 283929 : res = chrec_dont_know;
2463 : }
2464 :
2465 30616037 : else if (res != chrec_dont_know)
2466 : {
2467 30616037 : if (inner_loop
2468 1273635 : && def_bb->loop_father != inner_loop
2469 31231962 : && !flow_loop_nested_p (def_bb->loop_father, inner_loop))
2470 : /* ??? We could try to compute the overall effect of the loop here. */
2471 334 : res = chrec_dont_know;
2472 : else
2473 30615703 : res = instantiate_scev_r (instantiate_below, evolution_loop,
2474 : inner_loop, res,
2475 : fold_conversions, size_expr);
2476 : }
2477 :
2478 : /* Store the correct value to the cache. */
2479 32539451 : global_cache->set (si, res);
2480 32539451 : return res;
2481 : }
2482 :
2483 : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2484 : and EVOLUTION_LOOP, that were left under a symbolic form.
2485 :
2486 : CHREC is a polynomial chain of recurrence to be instantiated.
2487 :
2488 : CACHE is the cache of already instantiated values.
2489 :
2490 : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2491 : conversions that may wrap in signed/pointer type are folded, as long
2492 : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2493 : then we don't do such fold.
2494 :
2495 : SIZE_EXPR is used for computing the size of the expression to be
2496 : instantiated, and to stop if it exceeds some limit. */
2497 :
2498 : static tree
2499 60733947 : instantiate_scev_poly (edge instantiate_below,
2500 : class loop *evolution_loop, class loop *,
2501 : tree chrec, bool *fold_conversions, int size_expr)
2502 : {
2503 60733947 : tree op1;
2504 121467894 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2505 : get_chrec_loop (chrec),
2506 60733947 : CHREC_LEFT (chrec), fold_conversions,
2507 : size_expr);
2508 60733947 : if (op0 == chrec_dont_know)
2509 : return chrec_dont_know;
2510 :
2511 121033254 : op1 = instantiate_scev_r (instantiate_below, evolution_loop,
2512 : get_chrec_loop (chrec),
2513 60516627 : CHREC_RIGHT (chrec), fold_conversions,
2514 : size_expr);
2515 60516627 : if (op1 == chrec_dont_know)
2516 : return chrec_dont_know;
2517 :
2518 59746069 : if (CHREC_LEFT (chrec) != op0
2519 59746069 : || CHREC_RIGHT (chrec) != op1)
2520 : {
2521 7926612 : op1 = chrec_convert_rhs (chrec_type (op0), op1, NULL);
2522 7926612 : chrec = build_polynomial_chrec (CHREC_VARIABLE (chrec), op0, op1);
2523 : }
2524 :
2525 : return chrec;
2526 : }
2527 :
2528 : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2529 : and EVOLUTION_LOOP, that were left under a symbolic form.
2530 :
2531 : "C0 CODE C1" is a binary expression of type TYPE to be instantiated.
2532 :
2533 : CACHE is the cache of already instantiated values.
2534 :
2535 : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2536 : conversions that may wrap in signed/pointer type are folded, as long
2537 : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2538 : then we don't do such fold.
2539 :
2540 : SIZE_EXPR is used for computing the size of the expression to be
2541 : instantiated, and to stop if it exceeds some limit. */
2542 :
2543 : static tree
2544 24233643 : instantiate_scev_binary (edge instantiate_below,
2545 : class loop *evolution_loop, class loop *inner_loop,
2546 : tree chrec, enum tree_code code,
2547 : tree type, tree c0, tree c1,
2548 : bool *fold_conversions, int size_expr)
2549 : {
2550 24233643 : tree op1;
2551 24233643 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop,
2552 : c0, fold_conversions, size_expr);
2553 24233643 : if (op0 == chrec_dont_know)
2554 : return chrec_dont_know;
2555 :
2556 : /* While we eventually compute the same op1 if c0 == c1 the process
2557 : of doing this is expensive so the following short-cut prevents
2558 : exponential compile-time behavior. */
2559 23876166 : if (c0 != c1)
2560 : {
2561 23854083 : op1 = instantiate_scev_r (instantiate_below, evolution_loop, inner_loop,
2562 : c1, fold_conversions, size_expr);
2563 23854083 : if (op1 == chrec_dont_know)
2564 : return chrec_dont_know;
2565 : }
2566 : else
2567 : op1 = op0;
2568 :
2569 23806083 : if (c0 != op0
2570 23806083 : || c1 != op1)
2571 : {
2572 13664802 : op0 = chrec_convert (type, op0, NULL);
2573 13664802 : op1 = chrec_convert_rhs (type, op1, NULL);
2574 :
2575 13664802 : switch (code)
2576 : {
2577 7957991 : case POINTER_PLUS_EXPR:
2578 7957991 : case PLUS_EXPR:
2579 7957991 : return chrec_fold_plus (type, op0, op1);
2580 :
2581 881116 : case MINUS_EXPR:
2582 881116 : return chrec_fold_minus (type, op0, op1);
2583 :
2584 4825695 : case MULT_EXPR:
2585 4825695 : return chrec_fold_multiply (type, op0, op1);
2586 :
2587 0 : default:
2588 0 : gcc_unreachable ();
2589 : }
2590 : }
2591 :
2592 10141281 : return chrec ? chrec : fold_build2 (code, type, c0, c1);
2593 : }
2594 :
2595 : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2596 : and EVOLUTION_LOOP, that were left under a symbolic form.
2597 :
2598 : "CHREC" that stands for a convert expression "(TYPE) OP" is to be
2599 : instantiated.
2600 :
2601 : CACHE is the cache of already instantiated values.
2602 :
2603 : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2604 : conversions that may wrap in signed/pointer type are folded, as long
2605 : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2606 : then we don't do such fold.
2607 :
2608 : SIZE_EXPR is used for computing the size of the expression to be
2609 : instantiated, and to stop if it exceeds some limit. */
2610 :
2611 : static tree
2612 24536496 : instantiate_scev_convert (edge instantiate_below,
2613 : class loop *evolution_loop, class loop *inner_loop,
2614 : tree chrec, tree type, tree op,
2615 : bool *fold_conversions, int size_expr)
2616 : {
2617 24536496 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2618 : inner_loop, op,
2619 : fold_conversions, size_expr);
2620 :
2621 24536496 : if (op0 == chrec_dont_know)
2622 : return chrec_dont_know;
2623 :
2624 19500841 : if (fold_conversions)
2625 : {
2626 7585709 : tree tmp = chrec_convert_aggressive (type, op0, fold_conversions);
2627 7585709 : if (tmp)
2628 : return tmp;
2629 :
2630 : /* If we used chrec_convert_aggressive, we can no longer assume that
2631 : signed chrecs do not overflow, as chrec_convert does, so avoid
2632 : calling it in that case. */
2633 7088073 : if (*fold_conversions)
2634 : {
2635 8263 : if (chrec && op0 == op)
2636 : return chrec;
2637 :
2638 8263 : return fold_convert (type, op0);
2639 : }
2640 : }
2641 :
2642 18994942 : return chrec_convert (type, op0, NULL);
2643 : }
2644 :
2645 : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2646 : and EVOLUTION_LOOP, that were left under a symbolic form.
2647 :
2648 : CHREC is a BIT_NOT_EXPR or a NEGATE_EXPR expression to be instantiated.
2649 : Handle ~X as -1 - X.
2650 : Handle -X as -1 * X.
2651 :
2652 : CACHE is the cache of already instantiated values.
2653 :
2654 : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2655 : conversions that may wrap in signed/pointer type are folded, as long
2656 : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2657 : then we don't do such fold.
2658 :
2659 : SIZE_EXPR is used for computing the size of the expression to be
2660 : instantiated, and to stop if it exceeds some limit. */
2661 :
2662 : static tree
2663 337490 : instantiate_scev_not (edge instantiate_below,
2664 : class loop *evolution_loop, class loop *inner_loop,
2665 : tree chrec,
2666 : enum tree_code code, tree type, tree op,
2667 : bool *fold_conversions, int size_expr)
2668 : {
2669 337490 : tree op0 = instantiate_scev_r (instantiate_below, evolution_loop,
2670 : inner_loop, op,
2671 : fold_conversions, size_expr);
2672 :
2673 337490 : if (op0 == chrec_dont_know)
2674 : return chrec_dont_know;
2675 :
2676 278986 : if (op != op0)
2677 : {
2678 208288 : op0 = chrec_convert (type, op0, NULL);
2679 :
2680 208288 : switch (code)
2681 : {
2682 1903 : case BIT_NOT_EXPR:
2683 1903 : return chrec_fold_minus
2684 1903 : (type, fold_convert (type, integer_minus_one_node), op0);
2685 :
2686 206385 : case NEGATE_EXPR:
2687 206385 : return chrec_fold_multiply
2688 206385 : (type, fold_convert (type, integer_minus_one_node), op0);
2689 :
2690 0 : default:
2691 0 : gcc_unreachable ();
2692 : }
2693 : }
2694 :
2695 70698 : return chrec ? chrec : fold_build1 (code, type, op0);
2696 : }
2697 :
2698 : /* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
2699 : and EVOLUTION_LOOP, that were left under a symbolic form.
2700 :
2701 : CHREC is the scalar evolution to instantiate.
2702 :
2703 : CACHE is the cache of already instantiated values.
2704 :
2705 : Variable pointed by FOLD_CONVERSIONS is set to TRUE when the
2706 : conversions that may wrap in signed/pointer type are folded, as long
2707 : as the value of the chrec is preserved. If FOLD_CONVERSIONS is NULL
2708 : then we don't do such fold.
2709 :
2710 : SIZE_EXPR is used for computing the size of the expression to be
2711 : instantiated, and to stop if it exceeds some limit. */
2712 :
2713 : static tree
2714 364572000 : instantiate_scev_r (edge instantiate_below,
2715 : class loop *evolution_loop, class loop *inner_loop,
2716 : tree chrec,
2717 : bool *fold_conversions, int size_expr)
2718 : {
2719 : /* Give up if the expression is larger than the MAX that we allow. */
2720 364572000 : if (size_expr++ > param_scev_max_expr_size)
2721 11 : return chrec_dont_know;
2722 :
2723 364571989 : if (chrec == NULL_TREE
2724 505801436 : || automatically_generated_chrec_p (chrec)
2725 727151516 : || is_gimple_min_invariant (chrec))
2726 143221909 : return chrec;
2727 :
2728 221350080 : switch (TREE_CODE (chrec))
2729 : {
2730 110799703 : case SSA_NAME:
2731 110799703 : return instantiate_scev_name (instantiate_below, evolution_loop,
2732 : inner_loop, chrec,
2733 110799703 : fold_conversions, size_expr);
2734 :
2735 60733947 : case POLYNOMIAL_CHREC:
2736 60733947 : return instantiate_scev_poly (instantiate_below, evolution_loop,
2737 : inner_loop, chrec,
2738 60733947 : fold_conversions, size_expr);
2739 :
2740 24233643 : case POINTER_PLUS_EXPR:
2741 24233643 : case PLUS_EXPR:
2742 24233643 : case MINUS_EXPR:
2743 24233643 : case MULT_EXPR:
2744 24233643 : return instantiate_scev_binary (instantiate_below, evolution_loop,
2745 : inner_loop, chrec,
2746 : TREE_CODE (chrec), chrec_type (chrec),
2747 24233643 : TREE_OPERAND (chrec, 0),
2748 24233643 : TREE_OPERAND (chrec, 1),
2749 24233643 : fold_conversions, size_expr);
2750 :
2751 24536496 : CASE_CONVERT:
2752 24536496 : return instantiate_scev_convert (instantiate_below, evolution_loop,
2753 : inner_loop, chrec,
2754 24536496 : TREE_TYPE (chrec), TREE_OPERAND (chrec, 0),
2755 24536496 : fold_conversions, size_expr);
2756 :
2757 337490 : case NEGATE_EXPR:
2758 337490 : case BIT_NOT_EXPR:
2759 337490 : return instantiate_scev_not (instantiate_below, evolution_loop,
2760 : inner_loop, chrec,
2761 337490 : TREE_CODE (chrec), TREE_TYPE (chrec),
2762 337490 : TREE_OPERAND (chrec, 0),
2763 337490 : fold_conversions, size_expr);
2764 :
2765 0 : case ADDR_EXPR:
2766 0 : if (is_gimple_min_invariant (chrec))
2767 : return chrec;
2768 : /* Fallthru. */
2769 0 : case SCEV_NOT_KNOWN:
2770 0 : return chrec_dont_know;
2771 :
2772 0 : case SCEV_KNOWN:
2773 0 : return chrec_known;
2774 :
2775 708801 : default:
2776 708801 : if (CONSTANT_CLASS_P (chrec))
2777 : return chrec;
2778 708801 : return chrec_dont_know;
2779 : }
2780 : }
2781 :
2782 : /* Analyze all the parameters of the chrec that were left under a
2783 : symbolic form. INSTANTIATE_BELOW is the basic block that stops the
2784 : recursive instantiation of parameters: a parameter is a variable
2785 : that is defined in a basic block that dominates INSTANTIATE_BELOW or
2786 : a function parameter. */
2787 :
2788 : tree
2789 87470980 : instantiate_scev (edge instantiate_below, class loop *evolution_loop,
2790 : tree chrec)
2791 : {
2792 87470980 : tree res;
2793 :
2794 87470980 : if (dump_file && (dump_flags & TDF_SCEV))
2795 : {
2796 20 : fprintf (dump_file, "(instantiate_scev \n");
2797 20 : fprintf (dump_file, " (instantiate_below = %d -> %d)\n",
2798 20 : instantiate_below->src->index, instantiate_below->dest->index);
2799 20 : if (evolution_loop)
2800 20 : fprintf (dump_file, " (evolution_loop = %d)\n", evolution_loop->num);
2801 20 : fprintf (dump_file, " (chrec = ");
2802 20 : print_generic_expr (dump_file, chrec);
2803 20 : fprintf (dump_file, ")\n");
2804 : }
2805 :
2806 87470980 : bool destr = false;
2807 87470980 : if (!global_cache)
2808 : {
2809 37989116 : global_cache = new instantiate_cache_type;
2810 37989116 : destr = true;
2811 : }
2812 :
2813 87470980 : res = instantiate_scev_r (instantiate_below, evolution_loop,
2814 : NULL, chrec, NULL, 0);
2815 :
2816 87470980 : if (destr)
2817 : {
2818 37989116 : delete global_cache;
2819 37989116 : global_cache = NULL;
2820 : }
2821 :
2822 87470980 : if (dump_file && (dump_flags & TDF_SCEV))
2823 : {
2824 20 : fprintf (dump_file, " (res = ");
2825 20 : print_generic_expr (dump_file, res);
2826 20 : fprintf (dump_file, "))\n");
2827 : }
2828 :
2829 87470980 : return res;
2830 : }
2831 :
2832 : /* Similar to instantiate_parameters, but does not introduce the
2833 : evolutions in outer loops for LOOP invariants in CHREC, and does not
2834 : care about causing overflows, as long as they do not affect value
2835 : of an expression. */
2836 :
2837 : tree
2838 50588572 : resolve_mixers (class loop *loop, tree chrec, bool *folded_casts)
2839 : {
2840 50588572 : bool destr = false;
2841 50588572 : bool fold_conversions = false;
2842 50588572 : if (!global_cache)
2843 : {
2844 49888963 : global_cache = new instantiate_cache_type;
2845 49888963 : destr = true;
2846 : }
2847 :
2848 50588572 : tree ret = instantiate_scev_r (loop_preheader_edge (loop), loop, NULL,
2849 : chrec, &fold_conversions, 0);
2850 :
2851 50588572 : if (folded_casts && !*folded_casts)
2852 50588572 : *folded_casts = fold_conversions;
2853 :
2854 50588572 : if (destr)
2855 : {
2856 49888963 : delete global_cache;
2857 49888963 : global_cache = NULL;
2858 : }
2859 :
2860 50588572 : return ret;
2861 : }
2862 :
2863 : /* Entry point for the analysis of the number of iterations pass.
2864 : This function tries to safely approximate the number of iterations
2865 : the loop will run. When this property is not decidable at compile
2866 : time, the result is chrec_dont_know. Otherwise the result is a
2867 : scalar or a symbolic parameter. When the number of iterations may
2868 : be equal to zero and the property cannot be determined at compile
2869 : time, the result is a COND_EXPR that represents in a symbolic form
2870 : the conditions under which the number of iterations is not zero.
2871 :
2872 : Example of analysis: suppose that the loop has an exit condition:
2873 :
2874 : "if (b > 49) goto end_loop;"
2875 :
2876 : and that in a previous analysis we have determined that the
2877 : variable 'b' has an evolution function:
2878 :
2879 : "EF = {23, +, 5}_2".
2880 :
2881 : When we evaluate the function at the point 5, i.e. the value of the
2882 : variable 'b' after 5 iterations in the loop, we have EF (5) = 48,
2883 : and EF (6) = 53. In this case the value of 'b' on exit is '53' and
2884 : the loop body has been executed 6 times. */
2885 :
2886 : tree
2887 10601442 : number_of_latch_executions (class loop *loop)
2888 : {
2889 10601442 : edge exit;
2890 10601442 : class tree_niter_desc niter_desc;
2891 10601442 : tree may_be_zero;
2892 10601442 : tree res;
2893 :
2894 : /* Determine whether the number of iterations in loop has already
2895 : been computed. */
2896 10601442 : res = loop->nb_iterations;
2897 10601442 : if (res)
2898 : return res;
2899 :
2900 6977828 : may_be_zero = NULL_TREE;
2901 :
2902 6977828 : if (dump_file && (dump_flags & TDF_SCEV))
2903 1 : fprintf (dump_file, "(number_of_iterations_in_loop = \n");
2904 :
2905 6977828 : res = chrec_dont_know;
2906 6977828 : exit = single_exit (loop);
2907 :
2908 6977828 : if (exit && number_of_iterations_exit (loop, exit, &niter_desc, false))
2909 : {
2910 3520360 : may_be_zero = niter_desc.may_be_zero;
2911 3520360 : res = niter_desc.niter;
2912 : }
2913 :
2914 6977828 : if (res == chrec_dont_know
2915 3520360 : || !may_be_zero
2916 10498188 : || integer_zerop (may_be_zero))
2917 : ;
2918 540491 : else if (integer_nonzerop (may_be_zero))
2919 93 : res = build_int_cst (TREE_TYPE (res), 0);
2920 :
2921 540398 : else if (COMPARISON_CLASS_P (may_be_zero))
2922 540398 : res = fold_build3 (COND_EXPR, TREE_TYPE (res), may_be_zero,
2923 : build_int_cst (TREE_TYPE (res), 0), res);
2924 : else
2925 0 : res = chrec_dont_know;
2926 :
2927 6977828 : if (dump_file && (dump_flags & TDF_SCEV))
2928 : {
2929 1 : fprintf (dump_file, " (set_nb_iterations_in_loop = ");
2930 1 : print_generic_expr (dump_file, res);
2931 1 : fprintf (dump_file, "))\n");
2932 : }
2933 :
2934 6977828 : loop->nb_iterations = res;
2935 6977828 : return res;
2936 10601442 : }
2937 :
2938 :
2939 : /* Counters for the stats. */
2940 :
2941 : struct chrec_stats
2942 : {
2943 : unsigned nb_chrecs;
2944 : unsigned nb_affine;
2945 : unsigned nb_affine_multivar;
2946 : unsigned nb_higher_poly;
2947 : unsigned nb_chrec_dont_know;
2948 : unsigned nb_undetermined;
2949 : };
2950 :
2951 : /* Reset the counters. */
2952 :
2953 : static inline void
2954 0 : reset_chrecs_counters (struct chrec_stats *stats)
2955 : {
2956 0 : stats->nb_chrecs = 0;
2957 0 : stats->nb_affine = 0;
2958 0 : stats->nb_affine_multivar = 0;
2959 0 : stats->nb_higher_poly = 0;
2960 0 : stats->nb_chrec_dont_know = 0;
2961 0 : stats->nb_undetermined = 0;
2962 : }
2963 :
2964 : /* Dump the contents of a CHREC_STATS structure. */
2965 :
2966 : static void
2967 0 : dump_chrecs_stats (FILE *file, struct chrec_stats *stats)
2968 : {
2969 0 : fprintf (file, "\n(\n");
2970 0 : fprintf (file, "-----------------------------------------\n");
2971 0 : fprintf (file, "%d\taffine univariate chrecs\n", stats->nb_affine);
2972 0 : fprintf (file, "%d\taffine multivariate chrecs\n", stats->nb_affine_multivar);
2973 0 : fprintf (file, "%d\tdegree greater than 2 polynomials\n",
2974 : stats->nb_higher_poly);
2975 0 : fprintf (file, "%d\tchrec_dont_know chrecs\n", stats->nb_chrec_dont_know);
2976 0 : fprintf (file, "-----------------------------------------\n");
2977 0 : fprintf (file, "%d\ttotal chrecs\n", stats->nb_chrecs);
2978 0 : fprintf (file, "%d\twith undetermined coefficients\n",
2979 : stats->nb_undetermined);
2980 0 : fprintf (file, "-----------------------------------------\n");
2981 0 : fprintf (file, "%d\tchrecs in the scev database\n",
2982 0 : (int) scalar_evolution_info->elements ());
2983 0 : fprintf (file, "%d\tsets in the scev database\n", nb_set_scev);
2984 0 : fprintf (file, "%d\tgets in the scev database\n", nb_get_scev);
2985 0 : fprintf (file, "-----------------------------------------\n");
2986 0 : fprintf (file, ")\n\n");
2987 0 : }
2988 :
2989 : /* Gather statistics about CHREC. */
2990 :
2991 : static void
2992 0 : gather_chrec_stats (tree chrec, struct chrec_stats *stats)
2993 : {
2994 0 : if (dump_file && (dump_flags & TDF_STATS))
2995 : {
2996 0 : fprintf (dump_file, "(classify_chrec ");
2997 0 : print_generic_expr (dump_file, chrec);
2998 0 : fprintf (dump_file, "\n");
2999 : }
3000 :
3001 0 : stats->nb_chrecs++;
3002 :
3003 0 : if (chrec == NULL_TREE)
3004 : {
3005 0 : stats->nb_undetermined++;
3006 0 : return;
3007 : }
3008 :
3009 0 : switch (TREE_CODE (chrec))
3010 : {
3011 0 : case POLYNOMIAL_CHREC:
3012 0 : if (evolution_function_is_affine_p (chrec))
3013 : {
3014 0 : if (dump_file && (dump_flags & TDF_STATS))
3015 0 : fprintf (dump_file, " affine_univariate\n");
3016 0 : stats->nb_affine++;
3017 : }
3018 0 : else if (evolution_function_is_affine_multivariate_p (chrec, 0))
3019 : {
3020 0 : if (dump_file && (dump_flags & TDF_STATS))
3021 0 : fprintf (dump_file, " affine_multivariate\n");
3022 0 : stats->nb_affine_multivar++;
3023 : }
3024 : else
3025 : {
3026 0 : if (dump_file && (dump_flags & TDF_STATS))
3027 0 : fprintf (dump_file, " higher_degree_polynomial\n");
3028 0 : stats->nb_higher_poly++;
3029 : }
3030 :
3031 : break;
3032 :
3033 : default:
3034 : break;
3035 : }
3036 :
3037 0 : if (chrec_contains_undetermined (chrec))
3038 : {
3039 0 : if (dump_file && (dump_flags & TDF_STATS))
3040 0 : fprintf (dump_file, " undetermined\n");
3041 0 : stats->nb_undetermined++;
3042 : }
3043 :
3044 0 : if (dump_file && (dump_flags & TDF_STATS))
3045 0 : fprintf (dump_file, ")\n");
3046 : }
3047 :
3048 : /* Classify the chrecs of the whole database. */
3049 :
3050 : void
3051 0 : gather_stats_on_scev_database (void)
3052 : {
3053 0 : struct chrec_stats stats;
3054 :
3055 0 : if (!dump_file)
3056 0 : return;
3057 :
3058 0 : reset_chrecs_counters (&stats);
3059 :
3060 0 : hash_table<scev_info_hasher>::iterator iter;
3061 0 : scev_info_str *elt;
3062 0 : FOR_EACH_HASH_TABLE_ELEMENT (*scalar_evolution_info, elt, scev_info_str *,
3063 : iter)
3064 0 : gather_chrec_stats (elt->chrec, &stats);
3065 :
3066 0 : dump_chrecs_stats (dump_file, &stats);
3067 : }
3068 :
3069 :
3070 : /* Initialize the analysis of scalar evolutions for LOOPS. */
3071 :
3072 : void
3073 14842676 : scev_initialize (void)
3074 : {
3075 14842676 : gcc_assert (! scev_initialized_p ()
3076 : && loops_state_satisfies_p (cfun, LOOPS_NORMAL));
3077 :
3078 14842676 : scalar_evolution_info = hash_table<scev_info_hasher>::create_ggc (100);
3079 :
3080 53805292 : for (auto loop : loops_list (cfun, 0))
3081 9277264 : loop->nb_iterations = NULL_TREE;
3082 14842676 : }
3083 :
3084 : /* Return true if SCEV is initialized. */
3085 :
3086 : bool
3087 100354795 : scev_initialized_p (void)
3088 : {
3089 100354795 : return scalar_evolution_info != NULL;
3090 : }
3091 :
3092 : /* Cleans up the information cached by the scalar evolutions analysis
3093 : in the hash table. */
3094 :
3095 : void
3096 23596151 : scev_reset_htab (void)
3097 : {
3098 23596151 : if (!scalar_evolution_info)
3099 : return;
3100 :
3101 6098769 : scalar_evolution_info->empty ();
3102 : }
3103 :
3104 : /* Cleans up the information cached by the scalar evolutions analysis
3105 : in the hash table and in the loop->nb_iterations. */
3106 :
3107 : void
3108 12734898 : scev_reset (void)
3109 : {
3110 12734898 : scev_reset_htab ();
3111 :
3112 62832824 : for (auto loop : loops_list (cfun, 0))
3113 24628130 : loop->nb_iterations = NULL_TREE;
3114 12734898 : }
3115 :
3116 : /* Return true if the IV calculation in TYPE can overflow based on the knowledge
3117 : of the upper bound on the number of iterations of LOOP, the BASE and STEP
3118 : of IV.
3119 :
3120 : We do not use information whether TYPE can overflow so it is safe to
3121 : use this test even for derived IVs not computed every iteration or
3122 : hypotetical IVs to be inserted into code. */
3123 :
3124 : bool
3125 15096223 : iv_can_overflow_p (class loop *loop, tree type, tree base, tree step)
3126 : {
3127 15096223 : widest_int nit;
3128 15096223 : wide_int base_min, base_max, step_min, step_max, type_min, type_max;
3129 15096223 : signop sgn = TYPE_SIGN (type);
3130 15096223 : int_range_max r;
3131 :
3132 15096223 : if (integer_zerop (step))
3133 : return false;
3134 :
3135 30191846 : if (!INTEGRAL_TYPE_P (TREE_TYPE (base))
3136 28069632 : || !get_range_query (cfun)->range_of_expr (r, base)
3137 14034816 : || r.varying_p ()
3138 27507726 : || r.undefined_p ())
3139 2686964 : return true;
3140 :
3141 12409252 : base_min = r.lower_bound ();
3142 12409252 : base_max = r.upper_bound ();
3143 :
3144 24817945 : if (!INTEGRAL_TYPE_P (TREE_TYPE (step))
3145 24818504 : || !get_range_query (cfun)->range_of_expr (r, step)
3146 12409252 : || r.varying_p ()
3147 24739318 : || r.undefined_p ())
3148 79186 : return true;
3149 :
3150 12330066 : step_min = r.lower_bound ();
3151 12330066 : step_max = r.upper_bound ();
3152 :
3153 12330066 : if (!get_max_loop_iterations (loop, &nit))
3154 : return true;
3155 :
3156 11662873 : type_min = wi::min_value (type);
3157 11662873 : type_max = wi::max_value (type);
3158 :
3159 : /* Just sanity check that we don't see values out of the range of the type.
3160 : In this case the arithmetics below would overflow. */
3161 11662873 : gcc_checking_assert (wi::ge_p (base_min, type_min, sgn)
3162 : && wi::le_p (base_max, type_max, sgn));
3163 :
3164 : /* Account the possible increment in the last ieration. */
3165 11662873 : wi::overflow_type overflow = wi::OVF_NONE;
3166 11662873 : nit = wi::add (nit, 1, SIGNED, &overflow);
3167 11662873 : if (overflow)
3168 : return true;
3169 :
3170 : /* NIT is typeless and can exceed the precision of the type. In this case
3171 : overflow is always possible, because we know STEP is non-zero. */
3172 11662873 : if (wi::min_precision (nit, UNSIGNED) > TYPE_PRECISION (type))
3173 : return true;
3174 11417909 : wide_int nit2 = wide_int::from (nit, TYPE_PRECISION (type), UNSIGNED);
3175 :
3176 : /* If step can be positive, check that nit*step <= type_max-base.
3177 : This can be done by unsigned arithmetic and we only need to watch overflow
3178 : in the multiplication. The right hand side can always be represented in
3179 : the type. */
3180 11417909 : if (sgn == UNSIGNED || !wi::neg_p (step_max))
3181 : {
3182 11374342 : wi::overflow_type overflow = wi::OVF_NONE;
3183 11374342 : if (wi::gtu_p (wi::mul (step_max, nit2, UNSIGNED, &overflow),
3184 22748684 : type_max - base_max)
3185 22748684 : || overflow)
3186 5749045 : return true;
3187 : }
3188 : /* If step can be negative, check that nit*(-step) <= base_min-type_min. */
3189 5668864 : if (sgn == SIGNED && wi::neg_p (step_min))
3190 : {
3191 43916 : wi::overflow_type overflow, overflow2;
3192 43916 : overflow = overflow2 = wi::OVF_NONE;
3193 87832 : if (wi::gtu_p (wi::mul (wi::neg (step_min, &overflow2),
3194 : nit2, UNSIGNED, &overflow),
3195 87832 : base_min - type_min)
3196 87832 : || overflow || overflow2)
3197 16335 : return true;
3198 : }
3199 :
3200 : return false;
3201 15096223 : }
3202 :
3203 : /* Given EV with form of "(type) {inner_base, inner_step}_loop", this
3204 : function tries to derive condition under which it can be simplified
3205 : into "{(type)inner_base, (type)inner_step}_loop". The condition is
3206 : the maximum number that inner iv can iterate. */
3207 :
3208 : static tree
3209 40875 : derive_simple_iv_with_niters (tree ev, tree *niters)
3210 : {
3211 40875 : if (!CONVERT_EXPR_P (ev))
3212 : return ev;
3213 :
3214 40875 : tree inner_ev = TREE_OPERAND (ev, 0);
3215 40875 : if (TREE_CODE (inner_ev) != POLYNOMIAL_CHREC)
3216 : return ev;
3217 :
3218 40875 : tree init = CHREC_LEFT (inner_ev);
3219 40875 : tree step = CHREC_RIGHT (inner_ev);
3220 40875 : if (TREE_CODE (init) != INTEGER_CST
3221 40875 : || TREE_CODE (step) != INTEGER_CST || integer_zerop (step))
3222 7783 : return ev;
3223 :
3224 33092 : tree type = TREE_TYPE (ev);
3225 33092 : tree inner_type = TREE_TYPE (inner_ev);
3226 33092 : if (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (type))
3227 : return ev;
3228 :
3229 : /* Type conversion in "(type) {inner_base, inner_step}_loop" can be
3230 : folded only if inner iv won't overflow. We compute the maximum
3231 : number the inner iv can iterate before overflowing and return the
3232 : simplified affine iv. */
3233 33092 : tree delta;
3234 33092 : init = fold_convert (type, init);
3235 33092 : step = fold_convert (type, step);
3236 33092 : ev = build_polynomial_chrec (CHREC_VARIABLE (inner_ev), init, step);
3237 33092 : if (tree_int_cst_sign_bit (step))
3238 : {
3239 0 : tree bound = lower_bound_in_type (inner_type, inner_type);
3240 0 : delta = fold_build2 (MINUS_EXPR, type, init, fold_convert (type, bound));
3241 0 : step = fold_build1 (NEGATE_EXPR, type, step);
3242 : }
3243 : else
3244 : {
3245 33092 : tree bound = upper_bound_in_type (inner_type, inner_type);
3246 33092 : delta = fold_build2 (MINUS_EXPR, type, fold_convert (type, bound), init);
3247 : }
3248 33092 : *niters = fold_build2 (FLOOR_DIV_EXPR, type, delta, step);
3249 33092 : return ev;
3250 : }
3251 :
3252 : /* Checks whether use of OP in USE_LOOP behaves as a simple affine iv with
3253 : respect to WRTO_LOOP and returns its base and step in IV if possible
3254 : (see analyze_scalar_evolution_in_loop for more details on USE_LOOP
3255 : and WRTO_LOOP). If ALLOW_NONCONSTANT_STEP is true, we want step to be
3256 : invariant in LOOP. Otherwise we require it to be an integer constant.
3257 :
3258 : IV->no_overflow is set to true if we are sure the iv cannot overflow (e.g.
3259 : because it is computed in signed arithmetics). Consequently, adding an
3260 : induction variable
3261 :
3262 : for (i = IV->base; ; i += IV->step)
3263 :
3264 : is only safe if IV->no_overflow is false, or TYPE_OVERFLOW_UNDEFINED is
3265 : false for the type of the induction variable, or you can prove that i does
3266 : not wrap by some other argument. Otherwise, this might introduce undefined
3267 : behavior, and
3268 :
3269 : i = iv->base;
3270 : for (; ; i = (type) ((unsigned type) i + (unsigned type) iv->step))
3271 :
3272 : must be used instead.
3273 :
3274 : When IV_NITERS is not NULL, this function also checks case in which OP
3275 : is a conversion of an inner simple iv of below form:
3276 :
3277 : (outer_type){inner_base, inner_step}_loop.
3278 :
3279 : If type of inner iv has smaller precision than outer_type, it can't be
3280 : folded into {(outer_type)inner_base, (outer_type)inner_step}_loop because
3281 : the inner iv could overflow/wrap. In this case, we derive a condition
3282 : under which the inner iv won't overflow/wrap and do the simplification.
3283 : The derived condition normally is the maximum number the inner iv can
3284 : iterate, and will be stored in IV_NITERS. This is useful in loop niter
3285 : analysis, to derive break conditions when a loop must terminate, when is
3286 : infinite. */
3287 :
3288 : bool
3289 51403057 : simple_iv_with_niters (class loop *wrto_loop, class loop *use_loop,
3290 : tree op, affine_iv *iv, tree *iv_niters,
3291 : bool allow_nonconstant_step)
3292 : {
3293 51403057 : enum tree_code code;
3294 51403057 : tree type, ev, base, e;
3295 51403057 : wide_int extreme;
3296 51403057 : bool folded_casts;
3297 :
3298 51403057 : iv->base = NULL_TREE;
3299 51403057 : iv->step = NULL_TREE;
3300 51403057 : iv->no_overflow = false;
3301 :
3302 51403057 : type = TREE_TYPE (op);
3303 51403057 : if (!POINTER_TYPE_P (type)
3304 42273035 : && !INTEGRAL_TYPE_P (type))
3305 : return false;
3306 :
3307 49326733 : ev = analyze_scalar_evolution_in_loop (wrto_loop, use_loop, op,
3308 : &folded_casts);
3309 49326733 : if (chrec_contains_undetermined (ev)
3310 49326733 : || chrec_contains_symbols_defined_in_loop (ev, wrto_loop->num))
3311 12799715 : return false;
3312 :
3313 36527018 : if (tree_does_not_contain_chrecs (ev))
3314 : {
3315 16131618 : iv->base = ev;
3316 16131618 : tree ev_type = TREE_TYPE (ev);
3317 16131618 : if (POINTER_TYPE_P (ev_type))
3318 2670189 : ev_type = sizetype;
3319 :
3320 16131618 : iv->step = build_int_cst (ev_type, 0);
3321 16131618 : iv->no_overflow = true;
3322 16131618 : return true;
3323 : }
3324 :
3325 : /* If we can derive valid scalar evolution with assumptions. */
3326 20395400 : if (iv_niters && TREE_CODE (ev) != POLYNOMIAL_CHREC)
3327 40875 : ev = derive_simple_iv_with_niters (ev, iv_niters);
3328 :
3329 20395400 : if (TREE_CODE (ev) != POLYNOMIAL_CHREC)
3330 : return false;
3331 :
3332 20347713 : if (CHREC_VARIABLE (ev) != (unsigned) wrto_loop->num)
3333 : return false;
3334 :
3335 20347699 : iv->step = CHREC_RIGHT (ev);
3336 12975282 : if ((!allow_nonconstant_step && TREE_CODE (iv->step) != INTEGER_CST)
3337 33066329 : || tree_contains_chrecs (iv->step, NULL))
3338 268023 : return false;
3339 :
3340 20079676 : iv->base = CHREC_LEFT (ev);
3341 20079676 : if (tree_contains_chrecs (iv->base, NULL))
3342 : return false;
3343 :
3344 20079676 : iv->no_overflow = !folded_casts && nowrap_type_p (type);
3345 :
3346 20079676 : if (!iv->no_overflow
3347 20079676 : && !iv_can_overflow_p (wrto_loop, type, iv->base, iv->step))
3348 3789927 : iv->no_overflow = true;
3349 :
3350 : /* Try to simplify iv base:
3351 :
3352 : (signed T) ((unsigned T)base + step) ;; TREE_TYPE (base) == signed T
3353 : == (signed T)(unsigned T)base + step
3354 : == base + step
3355 :
3356 : If we can prove operation (base + step) doesn't overflow or underflow.
3357 : Specifically, we try to prove below conditions are satisfied:
3358 :
3359 : base <= UPPER_BOUND (type) - step ;;step > 0
3360 : base >= LOWER_BOUND (type) - step ;;step < 0
3361 :
3362 : This is done by proving the reverse conditions are false using loop's
3363 : initial conditions.
3364 :
3365 : The is necessary to make loop niter, or iv overflow analysis easier
3366 : for below example:
3367 :
3368 : int foo (int *a, signed char s, signed char l)
3369 : {
3370 : signed char i;
3371 : for (i = s; i < l; i++)
3372 : a[i] = 0;
3373 : return 0;
3374 : }
3375 :
3376 : Note variable I is firstly converted to type unsigned char, incremented,
3377 : then converted back to type signed char. */
3378 :
3379 20079676 : if (wrto_loop->num != use_loop->num)
3380 : return true;
3381 :
3382 19908665 : if (!CONVERT_EXPR_P (iv->base) || TREE_CODE (iv->step) != INTEGER_CST)
3383 : return true;
3384 :
3385 229855 : type = TREE_TYPE (iv->base);
3386 229855 : e = TREE_OPERAND (iv->base, 0);
3387 229855 : if (!tree_nop_conversion_p (type, TREE_TYPE (e))
3388 197872 : || TREE_CODE (e) != PLUS_EXPR
3389 109321 : || TREE_CODE (TREE_OPERAND (e, 1)) != INTEGER_CST
3390 312250 : || !tree_int_cst_equal (iv->step,
3391 82395 : fold_convert (type, TREE_OPERAND (e, 1))))
3392 166426 : return true;
3393 63429 : e = TREE_OPERAND (e, 0);
3394 63429 : if (!CONVERT_EXPR_P (e))
3395 : return true;
3396 35227 : base = TREE_OPERAND (e, 0);
3397 35227 : if (!useless_type_conversion_p (type, TREE_TYPE (base)))
3398 : return true;
3399 :
3400 26865 : if (tree_int_cst_sign_bit (iv->step))
3401 : {
3402 9121 : code = LT_EXPR;
3403 9121 : extreme = wi::min_value (type);
3404 : }
3405 : else
3406 : {
3407 17744 : code = GT_EXPR;
3408 17744 : extreme = wi::max_value (type);
3409 : }
3410 26865 : wi::overflow_type overflow = wi::OVF_NONE;
3411 26865 : extreme = wi::sub (extreme, wi::to_wide (iv->step),
3412 53730 : TYPE_SIGN (type), &overflow);
3413 26865 : if (overflow)
3414 : return true;
3415 26841 : e = fold_build2 (code, boolean_type_node, base,
3416 : wide_int_to_tree (type, extreme));
3417 26841 : e = simplify_using_initial_conditions (use_loop, e);
3418 26841 : if (!integer_zerop (e))
3419 : return true;
3420 :
3421 12989 : if (POINTER_TYPE_P (TREE_TYPE (base)))
3422 : code = POINTER_PLUS_EXPR;
3423 : else
3424 : code = PLUS_EXPR;
3425 :
3426 12989 : iv->base = fold_build2 (code, TREE_TYPE (base), base, iv->step);
3427 12989 : return true;
3428 51403057 : }
3429 :
3430 : /* Like simple_iv_with_niters, but return TRUE when OP behaves as a simple
3431 : affine iv unconditionally. */
3432 :
3433 : bool
3434 21120398 : simple_iv (class loop *wrto_loop, class loop *use_loop, tree op,
3435 : affine_iv *iv, bool allow_nonconstant_step)
3436 : {
3437 21120398 : return simple_iv_with_niters (wrto_loop, use_loop, op, iv,
3438 21120398 : NULL, allow_nonconstant_step);
3439 : }
3440 :
3441 : /* Finalize the scalar evolution analysis. */
3442 :
3443 : void
3444 14842677 : scev_finalize (void)
3445 : {
3446 14842677 : if (!scalar_evolution_info)
3447 : return;
3448 14842676 : scalar_evolution_info->empty ();
3449 14842676 : scalar_evolution_info = NULL;
3450 14842676 : free_numbers_of_iterations_estimates (cfun);
3451 : }
3452 :
3453 : /* Returns true if the expression EXPR is considered to be too expensive
3454 : for scev_const_prop. Sets *COND_OVERFLOW_P to true when the
3455 : expression might contain a sub-expression that is subject to undefined
3456 : overflow behavior and conditionally evaluated. */
3457 :
3458 : static bool
3459 10782927 : expression_expensive_p (tree expr, bool *cond_overflow_p,
3460 : hash_map<tree, uint64_t> &cache, uint64_t &cost)
3461 : {
3462 10782927 : enum tree_code code;
3463 :
3464 10782927 : if (is_gimple_val (expr))
3465 : return false;
3466 :
3467 4572449 : code = TREE_CODE (expr);
3468 4572449 : if (code == TRUNC_DIV_EXPR
3469 : || code == CEIL_DIV_EXPR
3470 : || code == FLOOR_DIV_EXPR
3471 : || code == ROUND_DIV_EXPR
3472 : || code == TRUNC_MOD_EXPR
3473 : || code == CEIL_MOD_EXPR
3474 : || code == FLOOR_MOD_EXPR
3475 4572449 : || code == ROUND_MOD_EXPR
3476 4572449 : || code == EXACT_DIV_EXPR)
3477 : {
3478 : /* Division by power of two is usually cheap, so we allow it.
3479 : Forbid anything else. */
3480 65776 : if (!integer_pow2p (TREE_OPERAND (expr, 1)))
3481 : return true;
3482 : }
3483 :
3484 4562723 : bool visited_p;
3485 4562723 : uint64_t &local_cost = cache.get_or_insert (expr, &visited_p);
3486 4562723 : if (visited_p)
3487 : {
3488 341 : uint64_t tem = cost + local_cost;
3489 341 : if (tem < cost)
3490 : return true;
3491 341 : cost = tem;
3492 341 : return false;
3493 : }
3494 4562382 : local_cost = 1;
3495 :
3496 4562382 : uint64_t op_cost = 0;
3497 4562382 : if (code == CALL_EXPR)
3498 : {
3499 140 : tree arg;
3500 140 : call_expr_arg_iterator iter;
3501 : /* Even though is_inexpensive_builtin might say true, we will get a
3502 : library call for popcount when backend does not have an instruction
3503 : to do so. We consider this to be expensive and generate
3504 : __builtin_popcount only when backend defines it. */
3505 140 : optab optab;
3506 140 : combined_fn cfn = get_call_combined_fn (expr);
3507 140 : switch (cfn)
3508 : {
3509 31 : CASE_CFN_POPCOUNT:
3510 31 : optab = popcount_optab;
3511 31 : goto bitcount_call;
3512 85 : CASE_CFN_CLZ:
3513 85 : optab = clz_optab;
3514 85 : goto bitcount_call;
3515 : CASE_CFN_CTZ:
3516 : optab = ctz_optab;
3517 140 : bitcount_call:
3518 : /* Check if opcode for popcount is available in the mode required. */
3519 140 : if (optab_handler (optab,
3520 140 : TYPE_MODE (TREE_TYPE (CALL_EXPR_ARG (expr, 0))))
3521 : == CODE_FOR_nothing)
3522 : {
3523 27 : machine_mode mode;
3524 27 : mode = TYPE_MODE (TREE_TYPE (CALL_EXPR_ARG (expr, 0)));
3525 27 : scalar_int_mode int_mode;
3526 :
3527 : /* If the mode is of 2 * UNITS_PER_WORD size, we can handle
3528 : double-word popcount by emitting two single-word popcount
3529 : instructions. */
3530 27 : if (is_a <scalar_int_mode> (mode, &int_mode)
3531 29 : && GET_MODE_SIZE (int_mode) == 2 * UNITS_PER_WORD
3532 2 : && (optab_handler (optab, word_mode)
3533 : != CODE_FOR_nothing))
3534 : break;
3535 : /* If popcount is available for a wider mode, we emulate the
3536 : operation for a narrow mode by first zero-extending the value
3537 : and then computing popcount in the wider mode. Analogue for
3538 : ctz. For clz we do the same except that we additionally have
3539 : to subtract the difference of the mode precisions from the
3540 : result. */
3541 25 : if (is_a <scalar_int_mode> (mode, &int_mode))
3542 : {
3543 25 : machine_mode wider_mode_iter;
3544 124 : FOR_EACH_WIDER_MODE (wider_mode_iter, mode)
3545 99 : if (optab_handler (optab, wider_mode_iter)
3546 : != CODE_FOR_nothing)
3547 0 : goto check_call_args;
3548 : /* Operation ctz may be emulated via clz in expand_ctz. */
3549 25 : if (optab == ctz_optab)
3550 : {
3551 0 : FOR_EACH_WIDER_MODE_FROM (wider_mode_iter, mode)
3552 0 : if (optab_handler (clz_optab, wider_mode_iter)
3553 : != CODE_FOR_nothing)
3554 0 : goto check_call_args;
3555 : }
3556 : }
3557 25 : return true;
3558 : }
3559 : break;
3560 :
3561 0 : default:
3562 0 : if (cfn == CFN_LAST
3563 0 : || !is_inexpensive_builtin (get_callee_fndecl (expr)))
3564 0 : return true;
3565 : break;
3566 : }
3567 :
3568 115 : check_call_args:
3569 345 : FOR_EACH_CALL_EXPR_ARG (arg, iter, expr)
3570 115 : if (expression_expensive_p (arg, cond_overflow_p, cache, op_cost))
3571 : return true;
3572 115 : *cache.get (expr) += op_cost;
3573 115 : cost += op_cost + 1;
3574 115 : return false;
3575 : }
3576 :
3577 4562242 : if (code == COND_EXPR)
3578 : {
3579 1899 : if (expression_expensive_p (TREE_OPERAND (expr, 0), cond_overflow_p,
3580 : cache, op_cost)
3581 1899 : || (EXPR_P (TREE_OPERAND (expr, 1))
3582 1898 : && EXPR_P (TREE_OPERAND (expr, 2)))
3583 : /* If either branch has side effects or could trap. */
3584 1891 : || TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
3585 1891 : || generic_expr_could_trap_p (TREE_OPERAND (expr, 1))
3586 1890 : || TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0))
3587 1890 : || generic_expr_could_trap_p (TREE_OPERAND (expr, 0))
3588 1890 : || expression_expensive_p (TREE_OPERAND (expr, 1), cond_overflow_p,
3589 : cache, op_cost)
3590 3697 : || expression_expensive_p (TREE_OPERAND (expr, 2), cond_overflow_p,
3591 : cache, op_cost))
3592 101 : return true;
3593 : /* Conservatively assume there's overflow for now. */
3594 1798 : *cond_overflow_p = true;
3595 1798 : *cache.get (expr) += op_cost;
3596 1798 : cost += op_cost + 1;
3597 1798 : return false;
3598 : }
3599 :
3600 4560343 : switch (TREE_CODE_CLASS (code))
3601 : {
3602 2378051 : case tcc_binary:
3603 2378051 : case tcc_comparison:
3604 2378051 : if (expression_expensive_p (TREE_OPERAND (expr, 1), cond_overflow_p,
3605 : cache, op_cost))
3606 : return true;
3607 :
3608 : /* Fallthru. */
3609 4557602 : case tcc_unary:
3610 4557602 : if (expression_expensive_p (TREE_OPERAND (expr, 0), cond_overflow_p,
3611 : cache, op_cost))
3612 : return true;
3613 4533787 : *cache.get (expr) += op_cost;
3614 4533787 : cost += op_cost + 1;
3615 4533787 : return false;
3616 :
3617 : default:
3618 : return true;
3619 : }
3620 : }
3621 :
3622 : bool
3623 3841572 : expression_expensive_p (tree expr, bool *cond_overflow_p)
3624 : {
3625 3841572 : hash_map<tree, uint64_t> cache;
3626 3841572 : uint64_t expanded_size = 0;
3627 3841572 : *cond_overflow_p = false;
3628 3841572 : return (expression_expensive_p (expr, cond_overflow_p, cache, expanded_size)
3629 : /* ??? Both the explicit unsharing and gimplification of expr will
3630 : expand shared trees to multiple copies.
3631 : Guard against exponential growth by counting the visits and
3632 : comparing againt the number of original nodes. Allow a tiny
3633 : bit of duplication to catch some additional optimizations. */
3634 3851468 : || expanded_size > (cache.elements () + 1));
3635 3841572 : }
3636 :
3637 : /* Match.pd function to match bitwise inductive expression.
3638 : .i.e.
3639 : _2 = 1 << _1;
3640 : _3 = ~_2;
3641 : tmp_9 = _3 & tmp_12; */
3642 : extern bool gimple_bitwise_induction_p (tree, tree *, tree (*)(tree));
3643 :
3644 : /* Return the inductive expression of bitwise operation if possible,
3645 : otherwise returns DEF. */
3646 : static tree
3647 20529 : analyze_and_compute_bitwise_induction_effect (class loop* loop,
3648 : tree phidef,
3649 : unsigned HOST_WIDE_INT niter)
3650 : {
3651 20529 : tree match_op[3],inv, bitwise_scev;
3652 20529 : tree type = TREE_TYPE (phidef);
3653 20529 : gphi* header_phi = NULL;
3654 :
3655 : /* Match things like op2(MATCH_OP[2]), op1(MATCH_OP[1]), phidef(PHIDEF)
3656 :
3657 : op2 = PHI <phidef, inv>
3658 : _1 = (int) bit_17;
3659 : _3 = 1 << _1;
3660 : op1 = ~_3;
3661 : phidef = op1 & op2; */
3662 20529 : if (!gimple_bitwise_induction_p (phidef, &match_op[0], NULL)
3663 102 : || TREE_CODE (match_op[2]) != SSA_NAME
3664 20529 : || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[2])))
3665 102 : || gimple_bb (header_phi) != loop->header
3666 20629 : || gimple_phi_num_args (header_phi) != 2)
3667 : return NULL_TREE;
3668 :
3669 100 : if (PHI_ARG_DEF_FROM_EDGE (header_phi, loop_latch_edge (loop)) != phidef)
3670 : return NULL_TREE;
3671 :
3672 100 : bitwise_scev = analyze_scalar_evolution (loop, match_op[1]);
3673 100 : bitwise_scev = instantiate_parameters (loop, bitwise_scev);
3674 :
3675 : /* Make sure bits is in range of type precision. */
3676 100 : if (TREE_CODE (bitwise_scev) != POLYNOMIAL_CHREC
3677 100 : || !INTEGRAL_TYPE_P (TREE_TYPE (bitwise_scev))
3678 100 : || !tree_fits_uhwi_p (CHREC_LEFT (bitwise_scev))
3679 100 : || tree_to_uhwi (CHREC_LEFT (bitwise_scev)) >= TYPE_PRECISION (type)
3680 200 : || !tree_fits_shwi_p (CHREC_RIGHT (bitwise_scev)))
3681 : return NULL_TREE;
3682 :
3683 100 : enum bit_op_kind
3684 : {
3685 : INDUCTION_BIT_CLEAR,
3686 : INDUCTION_BIT_IOR,
3687 : INDUCTION_BIT_XOR,
3688 : INDUCTION_BIT_RESET,
3689 : INDUCTION_ZERO,
3690 : INDUCTION_ALL
3691 : };
3692 :
3693 100 : enum bit_op_kind induction_kind;
3694 100 : enum tree_code code1
3695 100 : = gimple_assign_rhs_code (SSA_NAME_DEF_STMT (phidef));
3696 100 : enum tree_code code2
3697 100 : = gimple_assign_rhs_code (SSA_NAME_DEF_STMT (match_op[0]));
3698 :
3699 : /* BIT_CLEAR: A &= ~(1 << bit)
3700 : BIT_RESET: A ^= (1 << bit).
3701 : BIT_IOR: A |= (1 << bit)
3702 : BIT_ZERO: A &= (1 << bit)
3703 : BIT_ALL: A |= ~(1 << bit)
3704 : BIT_XOR: A ^= ~(1 << bit).
3705 : bit is induction variable. */
3706 100 : switch (code1)
3707 : {
3708 27 : case BIT_AND_EXPR:
3709 27 : induction_kind = code2 == BIT_NOT_EXPR
3710 27 : ? INDUCTION_BIT_CLEAR
3711 : : INDUCTION_ZERO;
3712 : break;
3713 49 : case BIT_IOR_EXPR:
3714 49 : induction_kind = code2 == BIT_NOT_EXPR
3715 49 : ? INDUCTION_ALL
3716 : : INDUCTION_BIT_IOR;
3717 : break;
3718 12 : case BIT_XOR_EXPR:
3719 12 : induction_kind = code2 == BIT_NOT_EXPR
3720 12 : ? INDUCTION_BIT_XOR
3721 : : INDUCTION_BIT_RESET;
3722 : break;
3723 : /* A ^ ~(1 << bit) is equal to ~(A ^ (1 << bit)). */
3724 12 : case BIT_NOT_EXPR:
3725 12 : gcc_assert (code2 == BIT_XOR_EXPR);
3726 : induction_kind = INDUCTION_BIT_XOR;
3727 : break;
3728 0 : default:
3729 0 : gcc_unreachable ();
3730 : }
3731 :
3732 37 : if (induction_kind == INDUCTION_ZERO)
3733 12 : return build_zero_cst (type);
3734 88 : if (induction_kind == INDUCTION_ALL)
3735 12 : return build_all_ones_cst (type);
3736 :
3737 152 : wide_int bits = wi::zero (TYPE_PRECISION (type));
3738 76 : HOST_WIDE_INT bit_start = tree_to_shwi (CHREC_LEFT (bitwise_scev));
3739 76 : HOST_WIDE_INT step = tree_to_shwi (CHREC_RIGHT (bitwise_scev));
3740 76 : HOST_WIDE_INT bit_final = bit_start + step * niter;
3741 :
3742 : /* bit_start, bit_final in range of [0,TYPE_PRECISION)
3743 : implies all bits are set in range. */
3744 76 : if (bit_final >= TYPE_PRECISION (type)
3745 76 : || bit_final < 0)
3746 : return NULL_TREE;
3747 :
3748 : /* Loop tripcount should be niter + 1. */
3749 1296 : for (unsigned i = 0; i != niter + 1; i++)
3750 : {
3751 1220 : bits = wi::set_bit (bits, bit_start);
3752 1220 : bit_start += step;
3753 : }
3754 :
3755 76 : bool inverted = false;
3756 76 : switch (induction_kind)
3757 : {
3758 : case INDUCTION_BIT_CLEAR:
3759 : code1 = BIT_AND_EXPR;
3760 : inverted = true;
3761 : break;
3762 : case INDUCTION_BIT_IOR:
3763 : code1 = BIT_IOR_EXPR;
3764 : break;
3765 : case INDUCTION_BIT_RESET:
3766 : code1 = BIT_XOR_EXPR;
3767 : break;
3768 : /* A ^= ~(1 << bit) is special, when loop tripcount is even,
3769 : it's equal to A ^= bits, else A ^= ~bits. */
3770 12 : case INDUCTION_BIT_XOR:
3771 12 : code1 = BIT_XOR_EXPR;
3772 12 : if (niter % 2 == 0)
3773 : inverted = true;
3774 : break;
3775 : default:
3776 : gcc_unreachable ();
3777 : }
3778 :
3779 : if (inverted)
3780 19 : bits = wi::bit_not (bits);
3781 :
3782 76 : inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge (loop));
3783 76 : return fold_build2 (code1, type, inv, wide_int_to_tree (type, bits));
3784 : }
3785 :
3786 : /* Match.pd function to match bitop with invariant expression
3787 : .i.e.
3788 : tmp_7 = _0 & _1; */
3789 : extern bool gimple_bitop_with_inv_p (tree, tree *, tree (*)(tree));
3790 :
3791 : /* Return the inductive expression of bitop with invariant if possible,
3792 : otherwise returns DEF. */
3793 : static tree
3794 74925 : analyze_and_compute_bitop_with_inv_effect (class loop* loop, tree phidef,
3795 : tree niter)
3796 : {
3797 74925 : tree match_op[2],inv;
3798 74925 : tree type = TREE_TYPE (phidef);
3799 74925 : gphi* header_phi = NULL;
3800 74925 : enum tree_code code;
3801 : /* match thing like op0 (match[0]), op1 (match[1]), phidef (PHIDEF)
3802 :
3803 : op1 = PHI <phidef, inv>
3804 : phidef = op0 & op1
3805 : if op0 is an invariant, it could change to
3806 : phidef = op0 & inv. */
3807 74925 : gimple *def;
3808 74925 : def = SSA_NAME_DEF_STMT (phidef);
3809 74925 : if (!(is_gimple_assign (def)
3810 27586 : && ((code = gimple_assign_rhs_code (def)), true)
3811 27586 : && (code == BIT_AND_EXPR || code == BIT_IOR_EXPR
3812 21893 : || code == BIT_XOR_EXPR)))
3813 : return NULL_TREE;
3814 :
3815 6397 : match_op[0] = gimple_assign_rhs1 (def);
3816 6397 : match_op[1] = gimple_assign_rhs2 (def);
3817 :
3818 6397 : if (expr_invariant_in_loop_p (loop, match_op[1]))
3819 221 : std::swap (match_op[0], match_op[1]);
3820 :
3821 6397 : if (TREE_CODE (match_op[1]) != SSA_NAME
3822 6397 : || !expr_invariant_in_loop_p (loop, match_op[0])
3823 315 : || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[1])))
3824 212 : || gimple_bb (header_phi) != loop->header
3825 6599 : || gimple_phi_num_args (header_phi) != 2)
3826 6195 : return NULL_TREE;
3827 :
3828 202 : if (PHI_ARG_DEF_FROM_EDGE (header_phi, loop_latch_edge (loop)) != phidef)
3829 : return NULL_TREE;
3830 :
3831 197 : enum tree_code code1
3832 197 : = gimple_assign_rhs_code (def);
3833 :
3834 197 : if (code1 == BIT_XOR_EXPR)
3835 : {
3836 51 : if (!tree_fits_uhwi_p (niter))
3837 : return NULL_TREE;
3838 19 : unsigned HOST_WIDE_INT niter_num;
3839 19 : niter_num = tree_to_uhwi (niter);
3840 19 : if (niter_num % 2 != 0)
3841 10 : match_op[0] = build_zero_cst (type);
3842 : }
3843 :
3844 165 : inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge (loop));
3845 165 : return fold_build2 (code1, type, inv, match_op[0]);
3846 : }
3847 :
3848 : /* Do final value replacement for LOOP, return true if we did anything. */
3849 :
3850 : bool
3851 686020 : final_value_replacement_loop (class loop *loop)
3852 : {
3853 : /* If we do not know exact number of iterations of the loop, we cannot
3854 : replace the final value. */
3855 686020 : edge exit = single_exit (loop);
3856 686020 : if (!exit)
3857 : return false;
3858 :
3859 458710 : tree niter = number_of_latch_executions (loop);
3860 458710 : if (niter == chrec_dont_know)
3861 : return false;
3862 :
3863 : /* Ensure that it is possible to insert new statements somewhere. */
3864 344367 : if (!single_pred_p (exit->dest))
3865 39251 : split_loop_exit_edge (exit);
3866 :
3867 : /* Set stmt insertion pointer. All stmts are inserted before this point. */
3868 :
3869 344367 : class loop *ex_loop
3870 688734 : = superloop_at_depth (loop,
3871 421494 : loop_depth (exit->dest->loop_father) + 1);
3872 :
3873 344367 : bool any = false;
3874 344367 : gphi_iterator psi;
3875 770893 : for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); )
3876 : {
3877 426526 : gphi *phi = psi.phi ();
3878 426526 : tree rslt = PHI_RESULT (phi);
3879 426526 : tree phidef = PHI_ARG_DEF_FROM_EDGE (phi, exit);
3880 426526 : tree def = phidef;
3881 852377 : if (virtual_operand_p (def))
3882 : {
3883 242036 : gsi_next (&psi);
3884 634073 : continue;
3885 : }
3886 :
3887 348278 : if (!POINTER_TYPE_P (TREE_TYPE (def))
3888 348167 : && !INTEGRAL_TYPE_P (TREE_TYPE (def)))
3889 : {
3890 73738 : gsi_next (&psi);
3891 73738 : continue;
3892 : }
3893 :
3894 110752 : bool folded_casts;
3895 110752 : def = analyze_scalar_evolution_in_loop (ex_loop, loop, def,
3896 : &folded_casts);
3897 :
3898 110752 : tree bitinv_def, bit_def;
3899 110752 : unsigned HOST_WIDE_INT niter_num;
3900 :
3901 110752 : if (def != chrec_dont_know)
3902 35827 : def = compute_overall_effect_of_inner_loop (ex_loop, def);
3903 :
3904 : /* Handle bitop with invariant induction expression.
3905 :
3906 : .i.e
3907 : for (int i =0 ;i < 32; i++)
3908 : tmp &= bit2;
3909 : if bit2 is an invariant in loop which could simple to
3910 : tmp &= bit2. */
3911 149850 : else if ((bitinv_def
3912 74925 : = analyze_and_compute_bitop_with_inv_effect (loop,
3913 : phidef, niter)))
3914 : def = bitinv_def;
3915 :
3916 : /* Handle bitwise induction expression.
3917 :
3918 : .i.e.
3919 : for (int i = 0; i != 64; i+=3)
3920 : res &= ~(1UL << i);
3921 :
3922 : RES can't be analyzed out by SCEV because it is not polynomially
3923 : expressible, but in fact final value of RES can be replaced by
3924 : RES & CONSTANT where CONSTANT all ones with bit {0,3,6,9,... ,63}
3925 : being cleared, similar for BIT_IOR_EXPR/BIT_XOR_EXPR. */
3926 74760 : else if (tree_fits_uhwi_p (niter)
3927 31058 : && (niter_num = tree_to_uhwi (niter)) != 0
3928 31039 : && niter_num < TYPE_PRECISION (TREE_TYPE (phidef))
3929 74760 : && (bit_def
3930 20529 : = analyze_and_compute_bitwise_induction_effect (loop,
3931 : phidef,
3932 : niter_num)))
3933 : def = bit_def;
3934 :
3935 110752 : bool cond_overflow_p;
3936 110752 : if (!tree_does_not_contain_chrecs (def)
3937 35510 : || chrec_contains_symbols_defined_in_loop (def, ex_loop->num)
3938 : /* Moving the computation from the loop may prolong life range
3939 : of some ssa names, which may cause problems if they appear
3940 : on abnormal edges. */
3941 35510 : || contains_abnormal_ssa_name_p (def)
3942 : /* Do not emit expensive expressions. The rationale is that
3943 : when someone writes a code like
3944 :
3945 : while (n > 45) n -= 45;
3946 :
3947 : he probably knows that n is not large, and does not want it
3948 : to be turned into n %= 45. */
3949 146262 : || expression_expensive_p (def, &cond_overflow_p))
3950 : {
3951 76263 : if (dump_file && (dump_flags & TDF_DETAILS))
3952 : {
3953 56 : fprintf (dump_file, "not replacing:\n ");
3954 56 : print_gimple_stmt (dump_file, phi, 0);
3955 56 : fprintf (dump_file, "\n");
3956 : }
3957 76263 : gsi_next (&psi);
3958 76263 : continue;
3959 : }
3960 :
3961 : /* Eliminate the PHI node and replace it by a computation outside
3962 : the loop. */
3963 34489 : if (dump_file)
3964 : {
3965 133 : fprintf (dump_file, "\nfinal value replacement:\n ");
3966 133 : print_gimple_stmt (dump_file, phi, 0);
3967 133 : fprintf (dump_file, " with expr: ");
3968 133 : print_generic_expr (dump_file, def);
3969 133 : fprintf (dump_file, "\n");
3970 : }
3971 34489 : any = true;
3972 : /* ??? Here we'd like to have a unshare_expr that would assign
3973 : shared sub-trees to new temporary variables either gimplified
3974 : to a GIMPLE sequence or to a statement list (keeping this a
3975 : GENERIC interface). */
3976 34489 : def = unshare_expr (def);
3977 34489 : auto loc = gimple_phi_arg_location (phi, exit->dest_idx);
3978 :
3979 : /* Create the replacement statements. */
3980 34489 : gimple_seq stmts;
3981 34489 : def = force_gimple_operand (def, &stmts, false, NULL_TREE);
3982 :
3983 : /* Propagate constants immediately, but leave an unused initialization
3984 : around to avoid invalidating the SCEV cache. */
3985 41246 : if (CONSTANT_CLASS_P (def) && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rslt))
3986 6756 : replace_uses_by (rslt, def);
3987 :
3988 : /* Remove the old phi after the gimplification to make sure the
3989 : SSA name is defined by a statement so that fold_stmt during
3990 : the gimplification does not crash. */
3991 34489 : remove_phi_node (&psi, false);
3992 34489 : gassign *ass = gimple_build_assign (rslt, def);
3993 34489 : gimple_set_location (ass, loc);
3994 34489 : gimple_seq_add_stmt (&stmts, ass);
3995 :
3996 : /* If def's type has undefined overflow and there were folded
3997 : casts, rewrite all stmts added for def into arithmetics
3998 : with defined overflow behavior. */
3999 34489 : if ((folded_casts
4000 425 : && ANY_INTEGRAL_TYPE_P (TREE_TYPE (def))
4001 718 : && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (def)))
4002 34914 : || cond_overflow_p)
4003 : {
4004 2058 : gimple_stmt_iterator gsi2;
4005 2058 : gsi2 = gsi_start (stmts);
4006 18804 : while (!gsi_end_p (gsi2))
4007 : {
4008 16746 : if (gimple_needing_rewrite_undefined (gsi_stmt (gsi2)))
4009 404 : rewrite_to_defined_unconditional (&gsi2);
4010 16746 : gsi_next (&gsi2);
4011 : }
4012 : }
4013 34489 : gimple_stmt_iterator gsi = gsi_after_labels (exit->dest);
4014 34489 : gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
4015 34489 : if (dump_file)
4016 : {
4017 133 : fprintf (dump_file, " final stmt:\n ");
4018 133 : print_gimple_stmt (dump_file, SSA_NAME_DEF_STMT (rslt), 0);
4019 133 : fprintf (dump_file, "\n");
4020 : }
4021 :
4022 : /* Re-fold immediate uses of the replaced def, but avoid
4023 : CFG manipulations from this function. For now only do
4024 : a single-level re-folding, not re-folding uses of
4025 : folded uses. */
4026 34489 : if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rslt))
4027 : {
4028 34488 : gimple *use_stmt;
4029 34488 : imm_use_iterator imm_iter;
4030 34488 : auto_vec<gimple *, 4> to_fold;
4031 68975 : FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, rslt)
4032 34487 : if (!stmt_can_throw_internal (cfun, use_stmt))
4033 34485 : to_fold.safe_push (use_stmt);
4034 : /* Delay folding until after the immediate use walk is completed
4035 : as we have an active ranger and that might walk immediate
4036 : uses of rslt again. See PR122502. */
4037 137949 : for (gimple *use_stmt : to_fold)
4038 : {
4039 34485 : gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
4040 34485 : if (fold_stmt (&gsi, follow_all_ssa_edges))
4041 1970 : update_stmt (gsi_stmt (gsi));
4042 : }
4043 34488 : }
4044 : }
4045 :
4046 : return any;
4047 : }
4048 :
4049 : #include "gt-tree-scalar-evolution.h"
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